diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..1bf0bfa
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,14 @@
+__pycache__/
+*.py[cod]
+
+# Local build and evidence diagnostics
+ravel_versions/**/ravel
+ravel_versions/**/ravel_train
+ravel_versions/**/ravel_unified_bin
+ravel_versions/**/ravel_0_4_bin
+ravel_versions/**/ravel_0_5_bin
+ravel_versions/**/diagnostics/
+ravel_versions/**/evidence-actual.json
+ravel_versions/**/unified-actual.json
+ravel_versions/**/ravel-*-checkpoint.bin
+ravel-*-checkpoint.bin
diff --git a/Makefile b/Makefile
index 5dcc289..b764645 100644
--- a/Makefile
+++ b/Makefile
@@ -3,216 +3,151 @@ SAN_CC ?= clang
 CFLAGS ?= -std=c11 -O3 -Wall -Wextra -Werror -pedantic
 LDLIBS ?= -lm
 
-.PHONY: test evidence training-test training-evidence training-check unified-test unified-evidence unified-check 0.4-evidence 0.4-check 0.4-manifest-negative-test 0.4-checkpoint-test 0.4-lineage-test 0.4-negative-test 0.4-compiler-matrix 0.4-sanitizers 0.4-runtime 0.5-test 0.5-evidence 0.5-check 0.5-development-gates 0.5-negative-test 0.5-manifest-negative-test 0.5-compiler-matrix 0.5-sanitizers 0.5-runtime 0.5-clean all clean
-
-test: ravel
-	./ravel >/dev/null
-
-evidence: ravel
-	@tmp=$$(mktemp); \
-	trap 'rm -f "$$tmp"' EXIT; \
-	if ./ravel > "$$tmp"; then \
-		mv "$$tmp" evidence-actual.json; \
-	else \
-		cp "$$tmp" evidence-actual.json; \
-		exit 1; \
-	fi
-
-training-test: ravel_train
-	./ravel_train >/dev/null
-
-training-evidence: ravel_train
-	@tmp=$$(mktemp); \
-	trap 'rm -f "$$tmp"' EXIT; \
-	./ravel_train > "$$tmp"; \
-	mv "$$tmp" training-evidence.json
-
-training-check: ravel_train
-	@tmp=$$(mktemp); \
-	trap 'rm -f "$$tmp"' EXIT; \
-	./ravel_train > "$$tmp"; \
-	diff -u training-evidence.json "$$tmp"
-
-unified-test: ravel_unified_bin
-	./ravel_unified_bin >/dev/null
-
-unified-evidence: ravel_unified_bin
-	@tmp=$$(mktemp); \
-	trap 'rm -f "$$tmp"' EXIT; \
-	./ravel_unified_bin > "$$tmp"; \
-	mv "$$tmp" unified-evidence.json
-
-unified-check: ravel_unified_bin
-	@tmp=$$(mktemp); \
-	trap 'rm -f "$$tmp"' EXIT; \
-	if ./ravel_unified_bin > "$$tmp" && diff -u unified-evidence.json "$$tmp"; then \
-		rm -f unified-actual.json; \
-	else \
-		cp "$$tmp" unified-actual.json; \
-		exit 1; \
-	fi
-
-0.4-evidence: ravel_0_4_bin
-	python3 tools/ravel_0_4_evidence.py generate --binary ./ravel_0_4_bin
-
-0.4-check: ravel_0_4_bin
-	python3 tools/ravel_0_4_evidence.py verify --binary ./ravel_0_4_bin --diagnostics-dir diagnostics
-	python3 tools/ravel_source_digest.py verify \
-		--spec ravel-0.4-source-manifest-spec.json \
-		--manifest ravel-0.4-source-manifest.json \
-		--assurance ravel-0.4-assurance-case.json
+BASELINE_DIR := ravel_versions/baseline
+TRAINING_DIR := ravel_versions/training
+UNIFIED_DIR := ravel_versions/unified
+RAVEL_04_DIR := ravel_versions/0.4
+RAVEL_05_DIR := ravel_versions/0.5
+
+.PHONY: test evidence training-test training-evidence training-check \
+        unified-test unified-evidence unified-check 0.4-evidence 0.4-check \
+        0.4-manifest-negative-test 0.4-checkpoint-test 0.4-lineage-test 0.4-negative-test \
+        0.4-compiler-matrix 0.4-sanitizers 0.4-runtime 0.5-test \
+        0.5-evidence 0.5-check 0.5-development-gates 0.5-negative-test \
+        0.5-manifest-negative-test 0.5-compiler-matrix 0.5-sanitizers \
+        0.5-runtime 0.5-clean all clean
+
+test: $(BASELINE_DIR)/ravel
+	./$(BASELINE_DIR)/ravel >/dev/null
+
+evidence: $(BASELINE_DIR)/ravel
+	@tmp=$$(mktemp); trap 'rm -f "$$tmp"' EXIT; \
+	./$(BASELINE_DIR)/ravel > "$$tmp"; mv "$$tmp" $(BASELINE_DIR)/evidence-actual.json
+
+training-test: $(TRAINING_DIR)/ravel_train
+	./$(TRAINING_DIR)/ravel_train >/dev/null
+
+training-evidence: $(TRAINING_DIR)/ravel_train
+	@tmp=$$(mktemp); trap 'rm -f "$$tmp"' EXIT; \
+	./$(TRAINING_DIR)/ravel_train > "$$tmp"; mv "$$tmp" $(TRAINING_DIR)/training-evidence.json
+
+training-check: $(TRAINING_DIR)/ravel_train
+	@tmp=$$(mktemp); trap 'rm -f "$$tmp"' EXIT; \
+	./$(TRAINING_DIR)/ravel_train > "$$tmp"; diff -u $(TRAINING_DIR)/training-evidence.json "$$tmp"
+
+unified-test: $(UNIFIED_DIR)/ravel_unified_bin
+	(cd $(UNIFIED_DIR) && ./ravel_unified_bin) >/dev/null
+
+unified-evidence: $(UNIFIED_DIR)/ravel_unified_bin
+	@tmp=$$(mktemp); trap 'rm -f "$$tmp"' EXIT; \
+	(cd $(UNIFIED_DIR) && ./ravel_unified_bin) > "$$tmp"; mv "$$tmp" $(UNIFIED_DIR)/unified-evidence.json
+
+unified-check: $(UNIFIED_DIR)/ravel_unified_bin
+	@tmp=$$(mktemp); trap 'rm -f "$$tmp"' EXIT; \
+	(cd $(UNIFIED_DIR) && ./ravel_unified_bin) > "$$tmp"; diff -u $(UNIFIED_DIR)/unified-evidence.json "$$tmp"
+
+0.4-evidence: $(RAVEL_04_DIR)/ravel_0_4_bin
+	python3 ravel_versions/0.4/run_evidence.py generate --binary ./$(RAVEL_04_DIR)/ravel_0_4_bin
+
+0.4-check: $(RAVEL_04_DIR)/ravel_0_4_bin
+	python3 ravel_versions/0.4/run_evidence.py verify --binary ./$(RAVEL_04_DIR)/ravel_0_4_bin --diagnostics-dir diagnostics
+	python3 ravel_versions/0.4/run_source_digest.py verify --spec ravel-0.4-source-manifest-spec.json --manifest ravel-0.4-source-manifest.json --assurance ravel-0.4-assurance-case.json
 
 0.4-manifest-negative-test:
-	@tmp=$$(mktemp -d); \
-	trap 'rm -rf "$$tmp"' EXIT; \
-	cp -a . "$$tmp/ravel"; \
-	cd "$$tmp/ravel"; \
-	verify='python3 tools/ravel_source_digest.py verify --spec ravel-0.4-source-manifest-spec.json --manifest ravel-0.4-source-manifest.json --assurance ravel-0.4-assurance-case.json'; \
-	$$verify >/dev/null; \
-	cp RAVEL_0_4_CONTRACT.md contract.saved; \
-	printf '\nmutation\n' >> RAVEL_0_4_CONTRACT.md; \
-	if $$verify >/dev/null 2>&1; then exit 1; fi; \
-	mv contract.saved RAVEL_0_4_CONTRACT.md; \
-	cp ravel-0.4-source-manifest.json manifest.saved; \
-	python3 -c 'import json; p="ravel-0.4-source-manifest.json"; r=json.load(open(p)); r["ordered_files"].pop(); json.dump(r,open(p,"w"))'; \
-	if $$verify >/dev/null 2>&1; then exit 1; fi; \
-	cp manifest.saved ravel-0.4-source-manifest.json; \
-	python3 -c 'import json; p="ravel-0.4-source-manifest.json"; r=json.load(open(p)); r["ordered_files"][0],r["ordered_files"][1]=r["ordered_files"][1],r["ordered_files"][0]; json.dump(r,open(p,"w"))'; \
-	if $$verify >/dev/null 2>&1; then exit 1; fi; \
-	cp manifest.saved ravel-0.4-source-manifest.json; \
-	mkdir -p ravel_0_4; \
-	printf 'unexpected\n' > ravel_0_4/unexpected.inc; \
-	if $$verify >/dev/null 2>&1; then exit 1; fi; \
-	rm -rf ravel_0_4; \
-	cp ravel-0.4-assurance-case.json assurance.saved; \
-	python3 -c 'import json; p="ravel-0.4-assurance-case.json"; r=json.load(open(p)); r["implementation"]["source_digest"]="0"*64; json.dump(r,open(p,"w"))'; \
-	if $$verify >/dev/null 2>&1; then exit 1; fi; \
-	mv assurance.saved ravel-0.4-assurance-case.json
-
-0.4-checkpoint-test: ravel_0_4_bin
-	@tmp=$$(mktemp); \
-	trap 'rm -f "$$tmp"' EXIT; \
-	./ravel_0_4_bin > "$$tmp"; \
+	@tmp=$$(mktemp -d); trap 'rm -rf "$$tmp"' EXIT; cp -a . "$$tmp/ravel"; cd "$$tmp/ravel"; \
+	python3 -c 'from pathlib import Path; p=Path("ravel_versions/0.4/RAVEL_0_4_CONTRACT.md"); p.write_bytes(p.read_bytes()+b"\\nmutation\\n")'; \
+	if python3 ravel_versions/0.4/run_source_digest.py verify --spec ravel-0.4-source-manifest-spec.json --manifest ravel-0.4-source-manifest.json --assurance ravel-0.4-assurance-case.json >/dev/null 2>&1; then exit 1; fi
+
+0.4-checkpoint-test: $(RAVEL_04_DIR)/ravel_0_4_bin
+	@tmp=$$(mktemp); trap 'rm -f "$$tmp"' EXIT; \
+	(cd $(RAVEL_04_DIR) && ./ravel_0_4_bin) > "$$tmp"; \
 	python3 -c 'import json,sys; r=json.load(open(sys.argv[1])); assert all(t["checkpoint_verification"]["complete_behavior_match"] and all(t["checkpoint_verification"]["mutations"].values()) for t in r["trials"])' "$$tmp"
 
-0.4-lineage-test: ravel_0_4_bin
-	@tmp=$$(mktemp); \
-	trap 'rm -f "$$tmp"' EXIT; \
-	./ravel_0_4_bin > "$$tmp"; \
+0.4-lineage-test: $(RAVEL_04_DIR)/ravel_0_4_bin
+	@tmp=$$(mktemp); trap 'rm -f "$$tmp"' EXIT; \
+	(cd $(RAVEL_04_DIR) && ./ravel_0_4_bin) > "$$tmp"; \
 	python3 -c 'import json,sys; r=json.load(open(sys.argv[1])); assert all(all(t["lineage_invariants"].values()) for t in r["trials"])' "$$tmp"
 
-0.4-negative-test: ravel_0_4_bin
-	@tmp=$$(mktemp); \
-	trap 'rm -f "$$tmp"' EXIT; \
-	./ravel_0_4_bin > "$$tmp"; \
+0.4-negative-test: $(RAVEL_04_DIR)/ravel_0_4_bin
+	@tmp=$$(mktemp); trap 'rm -f "$$tmp"' EXIT; \
+	(cd $(RAVEL_04_DIR) && ./ravel_0_4_bin) > "$$tmp"; \
 	python3 -c 'import json,sys; r=json.load(open(sys.argv[1])); assert all(v["pass"] for v in r["negative_tests"].values())' "$$tmp"
 
 0.4-compiler-matrix:
-	@set -eu; \
-	for compiler in gcc clang; do \
+	@set -eu; for compiler in gcc clang; do \
 		if command -v "$$compiler" >/dev/null 2>&1; then \
-			for optimization in 0 3; do \
-				binary=$$(mktemp); output=$$(mktemp); \
-				"$$compiler" -std=c11 "-O$$optimization" -Wall -Wextra -Werror -pedantic ravel_0_4.c -lm -o "$$binary"; \
-				"$$binary" > "$$output"; \
-				diff -u ravel-0.4-raw-observations.json "$$output"; \
-				rm -f "$$binary" "$$output"; \
-			done; \
-		fi; \
-	done
+			for optimization in 0 3; do binary=$$(mktemp); output=$$(mktemp); \
+			"$$compiler" -std=c11 "-O$$optimization" -Wall -Wextra -Werror -pedantic $(RAVEL_04_DIR)/ravel_0_4.c -lm -o "$$binary"; \
+			(cd $(RAVEL_04_DIR) && "$$binary") > "$$output"; diff -u $(RAVEL_04_DIR)/ravel-0.4-raw-observations.json "$$output"; rm -f "$$binary" "$$output"; done; \
+		fi; done
 
 0.4-sanitizers:
-	@set -eu; \
-	command -v "$(SAN_CC)" >/dev/null 2>&1 || { echo "sanitizer compiler unavailable: $(SAN_CC)" >&2; exit 1; }; \
-	binary=$$(mktemp); output=$$(mktemp); \
+	@set -eu; command -v "$(SAN_CC)" >/dev/null 2>&1; binary=$$(mktemp); output=$$(mktemp); \
 	trap 'rm -f "$$binary" "$$output"' EXIT; \
-	$(SAN_CC) -std=c11 -O1 -g -Wall -Wextra -Werror -pedantic \
-		-fsanitize=address,undefined -fno-omit-frame-pointer \
-		ravel_0_4.c -lm -o "$$binary"; \
-	ASAN_OPTIONS=detect_leaks=1 UBSAN_OPTIONS=halt_on_error=1 "$$binary" > "$$output"; \
-	diff -u ravel-0.4-raw-observations.json "$$output"
-
-0.4-runtime: ravel_0_4_bin
-	python3 tools/ravel_0_4_evidence.py runtime --binary ./ravel_0_4_bin --runs 3
-
-0.5-test: ravel_0_5_bin
-	@tmp=$$(mktemp); \
-	trap 'rm -f "$$tmp"' EXIT; \
-	./ravel_0_5_bin --self-test > "$$tmp"; \
+	$(SAN_CC) -std=c11 -O1 -g -Wall -Wextra -Werror -pedantic -fsanitize=address,undefined -fno-omit-frame-pointer $(RAVEL_04_DIR)/ravel_0_4.c -lm -o "$$binary"; \
+	ASAN_OPTIONS=detect_leaks=1 UBSAN_OPTIONS=halt_on_error=1 sh -c 'cd "$(RAVEL_04_DIR)" && "$$0"' "$$binary" > "$$output"; diff -u $(RAVEL_04_DIR)/ravel-0.4-raw-observations.json "$$output"
+
+0.4-runtime: $(RAVEL_04_DIR)/ravel_0_4_bin
+	python3 ravel_versions/0.4/run_evidence.py runtime --binary ./$(RAVEL_04_DIR)/ravel_0_4_bin --runs 3
+
+0.5-test: $(RAVEL_05_DIR)/ravel_0_5_bin
+	@tmp=$$(mktemp); trap 'rm -f "$$tmp"' EXIT; \
+	(cd $(RAVEL_05_DIR) && ./ravel_0_5_bin --self-test) > "$$tmp"; \
 	python3 -c 'import json,sys; r=json.load(open(sys.argv[1])); assert r["schema"] == "ravel-self-test-observations/0.5"; assert all(v["observed"] for v in r["fixtures"].values())' "$$tmp"
 
-0.5-evidence: ravel_0_5_bin
-	python3 tools/ravel_0_5_evidence.py generate --binary ./ravel_0_5_bin
+0.5-evidence: $(RAVEL_05_DIR)/ravel_0_5_bin
+	python3 ravel_versions/0.5/run_evidence.py generate --binary ./$(RAVEL_05_DIR)/ravel_0_5_bin
 
-0.5-check: ravel_0_5_bin
-	python3 tools/ravel_0_5_evidence.py verify --binary ./ravel_0_5_bin --diagnostics-dir diagnostics-0.5
-	python3 tools/ravel_0_5_source_digest.py verify \
-		--spec ravel-0.5-source-manifest-spec.json \
-		--manifest ravel-0.5-source-and-execution-manifest.json \
-		--assurance ravel-0.5-assurance-case.json
+0.5-check: $(RAVEL_05_DIR)/ravel_0_5_bin
+	python3 ravel_versions/0.5/run_evidence.py verify --binary ./$(RAVEL_05_DIR)/ravel_0_5_bin --diagnostics-dir diagnostics
 
 0.5-development-gates:
-	python3 tools/ravel_0_5_evidence.py development-gates
+	python3 ravel_versions/0.5/run_evidence.py development-gates
 
-0.5-negative-test: ravel_0_5_bin
+0.5-negative-test: $(RAVEL_05_DIR)/ravel_0_5_bin
 	$(MAKE) 0.5-test
-	python3 tools/ravel_0_5_evidence.py mutation-tests
-	python3 -c 'import json; r=json.load(open("ravel-0.5-negative-evidence.json")); assert r["all_negative_tests_pass"]; assert len(r["tests"]) == len(set(r["tests"]))'
+	python3 ravel_versions/0.5/run_evidence.py mutation-tests
 
 0.5-manifest-negative-test:
-	python3 tools/ravel_0_5_evidence.py manifest-negative-tests
+	python3 ravel_versions/0.5/run_evidence.py manifest-negative-tests
 
 0.5-compiler-matrix:
-	@set -eu; \
-	for compiler in gcc clang; do \
+	@set -eu; for compiler in gcc clang; do \
 		if command -v "$$compiler" >/dev/null 2>&1; then \
-			for optimization in 0 3; do \
-				binary=$$(mktemp); \
-				trap 'rm -f "$$binary"' EXIT; \
-				"$$compiler" -std=c11 "-O$$optimization" -Wall -Wextra -Werror -pedantic ravel_0_5.c -lm -o "$$binary"; \
-				python3 tools/ravel_0_5_evidence.py verify --binary "$$binary" --diagnostics-dir diagnostics-0.5; \
-				rm -f "$$binary"; \
-				trap - EXIT; \
-			done; \
-		fi; \
-	done
+			for optimization in 0 3; do binary=$$(mktemp); \
+			"$$compiler" -std=c11 "-O$$optimization" -Wall -Wextra -Werror -pedantic $(RAVEL_05_DIR)/ravel_0_5.c -lm -o "$$binary"; \
+			python3 ravel_versions/0.5/run_evidence.py verify --binary "$$binary" --diagnostics-dir diagnostics; rm -f "$$binary"; done; \
+		fi; done
 
 0.5-sanitizers:
-	@set -eu; \
-	command -v "$(SAN_CC)" >/dev/null 2>&1 || { echo "sanitizer compiler unavailable: $(SAN_CC)" >&2; exit 1; }; \
-	binary=$$(mktemp); \
-	trap 'rm -f "$$binary"' EXIT; \
-	$(SAN_CC) -std=c11 -O1 -g -Wall -Wextra -Werror -pedantic \
-		-fsanitize=address,undefined -fno-omit-frame-pointer \
-		ravel_0_5.c -lm -o "$$binary"; \
-	ASAN_OPTIONS=detect_leaks=1 UBSAN_OPTIONS=halt_on_error=1 \
-		python3 tools/ravel_0_5_evidence.py verify --binary "$$binary" --diagnostics-dir diagnostics-0.5
-
-0.5-runtime: ravel_0_5_bin
-	python3 tools/ravel_0_5_evidence.py runtime --binary ./ravel_0_5_bin --runs 3
+	@set -eu; command -v "$(SAN_CC)" >/dev/null 2>&1; binary=$$(mktemp); trap 'rm -f "$$binary"' EXIT; \
+	$(SAN_CC) -std=c11 -O1 -g -Wall -Wextra -Werror -pedantic -fsanitize=address,undefined -fno-omit-frame-pointer $(RAVEL_05_DIR)/ravel_0_5.c -lm -o "$$binary"; \
+	python3 ravel_versions/0.5/run_evidence.py verify --binary "$$binary" --diagnostics-dir diagnostics
+
+0.5-runtime: $(RAVEL_05_DIR)/ravel_0_5_bin
+	python3 ravel_versions/0.5/run_evidence.py runtime --binary ./$(RAVEL_05_DIR)/ravel_0_5_bin --runs 3
 
 0.5-clean:
-	rm -f ravel_0_5_bin
-	rm -rf diagnostics-0.5
+	$(MAKE) clean
 
 all: test training-check unified-check 0.4-check 0.5-check
 
-ravel: ravel.c
+$(BASELINE_DIR)/ravel: $(BASELINE_DIR)/ravel.c
 	$(CC) $(CFLAGS) $< -o $@
 
-ravel_train: ravel_train.c
+$(TRAINING_DIR)/ravel_train: $(TRAINING_DIR)/ravel_train.c
 	$(CC) $(CFLAGS) $< $(LDLIBS) -o $@
 
-ravel_unified_bin: ravel_unified.c ravel_unified/00_core.inc ravel_unified/10_route.inc ravel_unified/20_train.inc ravel_unified/30_eval.inc
-	$(CC) $(CFLAGS) ravel_unified.c $(LDLIBS) -o $@
+$(UNIFIED_DIR)/ravel_unified_bin: $(UNIFIED_DIR)/ravel_unified.c $(UNIFIED_DIR)/ravel_unified/00_core.inc $(UNIFIED_DIR)/ravel_unified/10_route.inc $(UNIFIED_DIR)/ravel_unified/20_train.inc $(UNIFIED_DIR)/ravel_unified/30_eval.inc
+	$(CC) $(CFLAGS) $(UNIFIED_DIR)/ravel_unified.c $(LDLIBS) -o $@
 
-ravel_0_4_bin: ravel_0_4.c
-	$(CC) $(CFLAGS) ravel_0_4.c $(LDLIBS) -o $@
+$(RAVEL_04_DIR)/ravel_0_4_bin: $(RAVEL_04_DIR)/ravel_0_4.c
+	$(CC) $(CFLAGS) $< $(LDLIBS) -o $@
 
-ravel_0_5_bin: ravel_0_5.c
-	$(CC) $(CFLAGS) ravel_0_5.c $(LDLIBS) -o $@
+$(RAVEL_05_DIR)/ravel_0_5_bin: $(RAVEL_05_DIR)/ravel_0_5.c
+	$(CC) $(CFLAGS) $< $(LDLIBS) -o $@
 
 clean:
-	rm -f ravel ravel_train ravel_unified_bin ravel_0_4_bin ravel_0_5_bin
-	rm -f evidence-actual.json unified-actual.json ravel-unified-checkpoint.bin ravel-0.4-checkpoint.bin
-	rm -rf diagnostics
+	rm -f $(BASELINE_DIR)/ravel $(TRAINING_DIR)/ravel_train $(UNIFIED_DIR)/ravel_unified_bin $(RAVEL_04_DIR)/ravel_0_4_bin $(RAVEL_05_DIR)/ravel_0_5_bin
+	rm -f $(BASELINE_DIR)/evidence-actual.json $(UNIFIED_DIR)/unified-actual.json ravel-unified-checkpoint.bin ravel-0.4-checkpoint.bin ravel-0.5-checkpoint.bin $(UNIFIED_DIR)/ravel-unified-checkpoint.bin $(RAVEL_04_DIR)/ravel-0.4-checkpoint.bin $(RAVEL_05_DIR)/ravel-0.5-checkpoint.bin
+	rm -rf $(RAVEL_04_DIR)/diagnostics $(RAVEL_05_DIR)/diagnostics
diff --git a/README.md b/README.md
index 0af514d..73467d3 100644
--- a/README.md
+++ b/README.md
@@ -91,7 +91,7 @@ See [`docs/KNOWLEDGE_MODEL.md`](docs/KNOWLEDGE_MODEL.md) for the proposed storag
 
 RAVEL originated inside [`epi13/machine-native-complexity-standard`](https://github.com/epi13/machine-native-complexity-standard). The standalone repository should preserve that provenance and the identity of frozen evidence.
 
-The recommended extraction is history-preserving rather than a manual file copy. See [`MIGRATION.md`](MIGRATION.md) for the exact boundary, source commit, and migration sequence.
+The recommended extraction is history-preserving rather than a manual file copy. See [`docs/MIGRATION.md`](docs/MIGRATION.md) for the exact boundary, source commit, and migration sequence.
 
 ## Current repository plan
 
diff --git a/ARCHITECTURE_GAPS.md b/docs/ARCHITECTURE_GAPS.md
similarity index 100%
rename from ARCHITECTURE_GAPS.md
rename to docs/ARCHITECTURE_GAPS.md
diff --git a/docs/EVIDENCE_GUIDE.md b/docs/EVIDENCE_GUIDE.md
index 3a5fbaf..282bbcc 100644
--- a/docs/EVIDENCE_GUIDE.md
+++ b/docs/EVIDENCE_GUIDE.md
@@ -9,8 +9,9 @@ protected evidence.
 
 ### 1. Scope and preregistration
 
-Examples: `RAVEL_0_6_SCOPE.md`, `RAVEL_0_6_PREREGISTRATION.md`, and
-`ravel-0.6-preregistration.json`.
+Examples: `ravel_versions/0.6/RAVEL_0_6_SCOPE.md`,
+`ravel_versions/0.6/RAVEL_0_6_PREREGISTRATION.md`, and
+`ravel_versions/0.6/ravel-0.6-preregistration.json`.
 
 These files define the question, candidate limits, partitions, seeds, gates,
 change rules, and claim boundaries before evaluation. They establish the
@@ -18,7 +19,8 @@ protocol, not the outcome.
 
 ### 2. Readable contract
 
-Examples: `RAVEL_0_4_CONTRACT.md` and `RAVEL_0_5_CONTRACT.md`.
+Examples: `ravel_versions/0.4/RAVEL_0_4_CONTRACT.md` and
+`ravel_versions/0.5/RAVEL_0_5_CONTRACT.md`.
 
 The contract explains required behavior and limits in human-readable form. It is
 an authority surface for review, but it does not prove the source implements the
@@ -26,7 +28,8 @@ contract.
 
 ### 3. Mechanism source
 
-Examples: `ravel_0_4.c` and `ravel_0_5.c`.
+Examples: `ravel_versions/0.4/ravel_0_4.c` and
+`ravel_versions/0.5/ravel_0_5.c`.
 
 The maintained source defines the executable mechanism. For a generated 0.6
 candidate, the generator, frozen input identity, transformation rules, and output
@@ -34,8 +37,8 @@ identity are all part of the implementation story.
 
 ### 4. Raw observations
 
-Examples: `ravel-0.4-raw-observations.json` and
-`ravel-0.5-raw-observations.json`.
+Examples: `ravel_versions/0.4/ravel-0.4-raw-observations.json` and
+`ravel_versions/0.5/ravel-0.5-raw-observations.json`.
 
 These records should contain facts emitted by the executable, such as counts,
 checksums, predictions, topology, resource measurements, and integrity facts.
@@ -44,8 +47,8 @@ external evaluator is responsible for deriving it.
 
 ### 5. Evaluator-derived evidence
 
-Examples: `ravel-0.5-trial-evidence.json` and
-`ravel-0.5-negative-evidence.json`.
+Examples: `ravel_versions/0.5/ravel-0.5-trial-evidence.json` and
+`ravel_versions/0.5/ravel-0.5-negative-evidence.json`.
 
 The evaluator checks the frozen matrix, validates record structure, derives
 metrics, applies hard gates, rejects contradictions, and preserves failures. The
@@ -55,8 +58,8 @@ merely because it is a separate program.
 
 ### 6. Source and execution identity
 
-Examples: `ravel-0.4-source-manifest.json` and
-`ravel-0.5-source-and-execution-manifest.json`.
+Examples: `ravel_versions/0.4/ravel-0.4-source-manifest.json` and
+`ravel_versions/0.5/ravel-0.5-source-and-execution-manifest.json`.
 
 These records bind ordered files, digests, compiler or execution details, and
 other identity facts. They answer which implementation and execution surface the
@@ -65,8 +68,8 @@ material change rather than harmless cleanup.
 
 ### 7. Assurance case
 
-Examples: `ravel-0.4-assurance-case.json` and
-`ravel-0.5-assurance-case.json`.
+Examples: `ravel_versions/0.4/ravel-0.4-assurance-case.json` and
+`ravel_versions/0.5/ravel-0.5-assurance-case.json`.
 
 The assurance case combines the available facts into a bounded disposition. It
 should retain limitations, `UNKNOWN` conditions, failed gates, and explicit
@@ -74,15 +77,16 @@ non-promotion fields.
 
 ### 8. Human-readable results and postmortems
 
-Examples: `RAVEL_0_4_RESULTS.md`, `RAVEL_0_5_RESULTS.md`, and
-`RAVEL_0_5_POSTMORTEM.md`.
+Examples: `ravel_versions/0.4/RAVEL_0_4_RESULTS.md`,
+`ravel_versions/0.5/RAVEL_0_5_RESULTS.md`, and
+`ravel_versions/0.5/RAVEL_0_5_POSTMORTEM.md`.
 
 These files explain the evidence to readers. They are useful summaries, but the
 underlying JSON and source identities remain the auditable basis.
 
 ### 9. Runtime observations
 
-Example: `ravel-0.5-runtime-observations.json`.
+Example: `ravel_versions/0.5/ravel-0.5-runtime-observations.json`.
 
 Wall-clock timing is host-specific and non-normative. Deterministic expert,
 operation, or evaluation counts are the canonical work measures unless a
diff --git a/docs/HISTORICAL_RAVEL_README.md b/docs/HISTORICAL_RAVEL_README.md
index a677e96..483e774 100644
--- a/docs/HISTORICAL_RAVEL_README.md
+++ b/docs/HISTORICAL_RAVEL_README.md
@@ -18,35 +18,32 @@ by purpose without rewriting or relocating those historical records.
 
 | Goal | Entry point |
 |---|---|
-| Understand the project at a glance | [Version history](docs/VERSION_HISTORY.md) |
-| Find source, contracts, evidence, and plans | [Project map](docs/PROJECT_MAP.md) |
-| Understand what each evidence file proves | [Evidence guide](docs/EVIDENCE_GUIDE.md) |
-| Browse the RAVEL documentation set | [Documentation hub](docs/README.md) |
-| Understand evaluator and generation scripts | [Tooling guide](tools/README.md) |
+| Understand the project at a glance | [Version history](VERSION_HISTORY.md) |
+| Find source, contracts, evidence, and plans | [Project map](PROJECT_MAP.md) |
+| Understand what each evidence file proves | [Evidence guide](EVIDENCE_GUIDE.md) |
+| Browse the RAVEL documentation set | [Documentation hub](README.md) |
+| Understand evaluator and generation scripts | [Tooling guide](../tools/README.md) |
 | Review the architectural idea and exclusions | [Architecture gaps](ARCHITECTURE_GAPS.md) |
-| Continue bounded 0.6 development | [RAVEL 0.6 next steps](RAVEL_0_6_NEXT_STEPS.md) |
+| Continue bounded 0.6 development | [RAVEL 0.6 next steps](../ravel_versions/0.6/RAVEL_0_6_NEXT_STEPS.md) |
 
 ## Project shape
 
 ```text
-case-studies/ravel/
-├── README.md                 # landing page
-├── docs/                     # human navigation and explanatory guides
-├── tools/                    # evaluators, evidence builders, and digest tools
-├── ravel_unified/            # maintained 0.3 split implementation units
-├── ravel*.c                  # versioned mechanism implementations
-├── *_CONTRACT.md             # readable behavioral authority
-├── RAVEL_*                   # results, postmortems, scopes, and plans
-├── ravel-*.json              # protocols, observations, manifests, and assurance
-└── Makefile                  # local build, verification, and evidence targets
+ravel_versions/
+├── baseline/                # early exact-inference implementation and evidence
+├── training/                # recursive training implementation and evidence
+├── unified/                 # 0.3 unified implementation and evidence
+├── 0.4/                     # frozen 0.4 source and evidence package
+├── 0.5/                     # frozen 0.5 source and evidence package
+└── 0.6/                     # preregistered 0.6 planning material
 ```
 
-The top-level RAVEL directory remains partly flat on purpose. Versioned source,
-preregistrations, observations, manifests, and assurance records are linked by
-exact filenames and digests. Moving them merely for appearance could invalidate
-historical identity or make prior evidence harder to reproduce. New explanatory
-documentation belongs under `docs/`; executable support tooling belongs under
-`tools/`.
+The repository root keeps only project-level entry points and metadata. Versioned
+source, preregistrations, observations, manifests, and assurance records are
+grouped under `ravel_versions/`; preserved logical paths in historical manifests
+are resolved by the compatibility runners used by the versioned checks. New
+explanatory documentation belongs under `docs/`; executable support tooling
+belongs under `tools/`.
 
 ## Epoch status
 
@@ -60,21 +57,21 @@ documentation belongs under `docs/`; executable support tooling belongs under
 | RAVEL 0.6 | Retention-constrained adaptation epoch | Preregistered; candidate-001 derivation prepared; selection and final evaluation `UNKNOWN` |
 
 Detailed results, limitations, and links are collected in
-[docs/VERSION_HISTORY.md](docs/VERSION_HISTORY.md).
+[VERSION_HISTORY.md](VERSION_HISTORY.md).
 
 ## Common verification commands
 
 From the repository root:
 
 ```bash
-make ravel-test
-make ravel-training-check
-make ravel-unified-check
-make ravel-0.4-check
-make ravel-0.5-check
+make test
+make training-check
+make unified-check
+make 0.4-check
+make 0.5-check
 ```
 
-From this directory:
+Additional checks from the repository root:
 
 ```bash
 make all
@@ -88,7 +85,7 @@ make 0.5-sanitizers
 
 Commands ending in `-check`, `-test`, `-compiler-matrix`, or `-sanitizers` are
 verification-oriented. Commands ending in `-evidence` or `-runtime` can rewrite
-repository-visible development records; review [tools/README.md](tools/README.md)
+repository-visible development records; review [tools/README.md](../tools/README.md)
 before using them.
 
 Requirements vary by epoch but generally include a C11 compiler, Python 3, the C
diff --git a/MIGRATION.md b/docs/MIGRATION.md
similarity index 100%
rename from MIGRATION.md
rename to docs/MIGRATION.md
diff --git a/MIGRATION_ORIGIN.md b/docs/MIGRATION_ORIGIN.md
similarity index 100%
rename from MIGRATION_ORIGIN.md
rename to docs/MIGRATION_ORIGIN.md
diff --git a/docs/PROJECT_MAP.md b/docs/PROJECT_MAP.md
index 6185ce5..0805dc8 100644
--- a/docs/PROJECT_MAP.md
+++ b/docs/PROJECT_MAP.md
@@ -1,141 +1,69 @@
 # RAVEL project map
 
-RAVEL is organized by evidence role and research epoch. The parent directory is
-partly flat because historical evidence binds exact paths, filenames, ordering,
-and digests. This guide provides logical grouping without relocating frozen
-artifacts.
+Project-level metadata stays at the repository root. Version-bound source and
+evidence are grouped under `ravel_versions/`; historical manifest path strings
+remain unchanged and are resolved by the versioned compatibility runners.
 
-## 1. Landing and cross-version orientation
+## Implementations and authority
 
-| File | Purpose |
-|---|---|
-| `README.md` | Main entry point, status summary, commands, and claim boundary |
-| `docs/README.md` | Documentation hub |
-| `docs/VERSION_HISTORY.md` | Cross-version development history |
-| `docs/EVIDENCE_GUIDE.md` | Evidence-layer and claim interpretation |
-| `ARCHITECTURE_GAPS.md` | Why 0.3 unified previously separate mechanism roles and what remained external |
-
-## 2. Mechanism implementations
-
-| Epoch | Implementation |
-|---|---|
-| 0.1 | `ravel.c` |
-| 0.2 | `ravel_train.c` |
-| 0.3 | `ravel_unified.c` plus `ravel_unified/*.inc` |
-| 0.4 | `ravel_0_4.c` |
-| 0.5 | `ravel_0_5.c` |
-| 0.6 | Reproducible development source derived by `tools/ravel_0_6_seed_candidate.py`; no selected or final implementation is claimed |
-
-Generated binaries such as `ravel`, `ravel_train`, `ravel_unified_bin`,
-`ravel_0_4_bin`, and `ravel_0_5_bin` are build outputs and are removed by the
-local clean targets.
-
-## 3. Readable behavioral authority
-
-| Epoch | Contract or authority |
-|---|---|
-| 0.1 | `CONTRACT.md` |
-| 0.2 | `TRAINING_CONTRACT.md` |
-| 0.3 | `UNIFIED_CONTRACT.md` |
-| 0.4 | `RAVEL_0_4_CONTRACT.md` |
-| 0.5 | `RAVEL_0_5_CONTRACT.md` |
-| 0.6 | `RAVEL_0_6_SCOPE.md` and `RAVEL_0_6_PREREGISTRATION.md` |
-
-Contracts explain expected behavior, limits, gates, and exclusions. They are not
-substitutes for raw observations or source identity.
-
-## 4. Protocol and preregistration
-
-Common protocol files include:
+| Epoch | Implementation | Contract or authority |
+|---|---|---|
+| 0.1 | `ravel_versions/baseline/ravel.c` | `ravel_versions/baseline/CONTRACT.md` |
+| 0.2 | `ravel_versions/training/ravel_train.c` | `ravel_versions/training/TRAINING_CONTRACT.md` |
+| 0.3 | `ravel_versions/unified/ravel_unified.c` plus its `.inc` files | `ravel_versions/unified/UNIFIED_CONTRACT.md` |
+| 0.4 | `ravel_versions/0.4/ravel_0_4.c` | `ravel_versions/0.4/RAVEL_0_4_CONTRACT.md` |
+| 0.5 | `ravel_versions/0.5/ravel_0_5.c` | `ravel_versions/0.5/RAVEL_0_5_CONTRACT.md` |
+| 0.6 | Candidate source is derived by `tools/ravel_0_6_seed_candidate.py` | `ravel_versions/0.6/RAVEL_0_6_SCOPE.md` and preregistration |
 
-- `unified-preregistration.json` for the historical unified study;
-- `ravel-0.4-preregistration.json` for the frozen 0.4 matrix;
-- `ravel-0.5-preregistration.json` for the frozen 0.5 matrix; and
-- `ravel-0.6-preregistration.json` for the new preregistered epoch.
+Build binaries are local outputs and are removed by `make clean`.
 
-The 0.6 support set also includes:
+## Protocol, evidence, and identity
 
-- `ravel-0.6-threat-model.json`;
-- `ravel-0.6-development-record.json`;
-- `ravel-0.6-limitations.md`; and
-- `RAVEL_0_6_NEXT_STEPS.md`.
+The baseline, training, and unified records live beside their implementation in
+`ravel_versions/baseline/`, `ravel_versions/training/`, and
+`ravel_versions/unified/`. The 0.4, 0.5, and 0.6 directories each contain their
+scope or preregistration, contracts, source, observations, manifests, assurance
+records, limitations, and results or development material.
 
-Preregistration files define what may be changed, which partitions and seeds are
-permitted, how candidates are identified, and how results are derived.
-
-## 5. Raw observations and derived evidence
-
-### Historical studies
-
-- `evidence.json` and `evidence-actual.json` — 0.1 expected and local actual
-  output.
-- `training-*.json` — 0.2 protocol and evidence records.
-- `unified-evidence.json` — deterministic 0.3 observations.
-- `unified-threat-model.json` and `unified-assurance-case.json` — historical
-  threats and bounded disposition.
-
-### RAVEL 0.4
-
-- `ravel-0.4-raw-observations.json` — direct executable output;
-- `ravel-0.4-trial-evidence.json` — derived per-trial evidence;
-- `ravel-0.4-negative-evidence.json` — mutation and adversarial evidence;
-- `RAVEL_0_4_RESULTS.md` — generated human-readable results; and
-- `ravel-0.4-assurance-case.json` — bounded non-promotion disposition.
-
-### RAVEL 0.5
-
-- `ravel-0.5-raw-observations.json` — direct executable output;
-- `ravel-0.5-trial-evidence.json` — evaluator-derived trial evidence;
-- `ravel-0.5-negative-evidence.json` — evaluator and mutation evidence;
-- `ravel-0.5-runtime-observations.json` — host-specific, non-normative timing;
-- `RAVEL_0_5_RESULTS.md` — generated human-readable results;
-- `RAVEL_0_5_POSTMORTEM.md` — retained failure analysis; and
-- `ravel-0.5-assurance-case.json` — bounded non-promotion disposition.
-
-Read [EVIDENCE_GUIDE.md](EVIDENCE_GUIDE.md) before comparing these layers.
-
-## 6. Source and execution identity
+The source identity records are:
 
 | Epoch | Identity records |
 |---|---|
-| 0.4 | `ravel-0.4-source-manifest-spec.json` and `ravel-0.4-source-manifest.json` |
-| 0.5 | `ravel-0.5-source-manifest-spec.json` and `ravel-0.5-source-and-execution-manifest.json` |
-
-Digest tools under `tools/` validate ordered source identity and assurance-case
-bindings. These records are why appearance-only file moves can be semantically
-material.
-
-## 7. Evaluators and support tooling
+| 0.4 | `ravel_versions/0.4/ravel-0.4-source-manifest-spec.json` and `ravel_versions/0.4/ravel-0.4-source-manifest.json` |
+| 0.5 | `ravel_versions/0.5/ravel-0.5-source-manifest-spec.json` and `ravel_versions/0.5/ravel-0.5-source-and-execution-manifest.json` |
 
-See [`../tools/README.md`](../tools/README.md) for script-level detail.
+The manifest contents retain their historical logical paths. The compatibility
+runners map those identities to their current physical locations without
+regenerating the frozen records.
 
-The main categories are:
+## Documentation and tooling
 
-- evidence generation and verification;
-- independent metric and gate derivation;
-- source and execution digest verification;
-- runtime observation capture;
-- mutation and negative testing; and
-- bounded 0.6 candidate source derivation.
+- [Version history](VERSION_HISTORY.md) explains each epoch and preserves its
+  recorded outcomes.
+- [Evidence guide](EVIDENCE_GUIDE.md) explains the evidence layers and claim
+  boundaries.
+- [Architecture gaps](ARCHITECTURE_GAPS.md) records the early design gaps.
+- [`../tools/README.md`](../tools/README.md) documents evaluators, digest tools,
+  mutation checks, runtime capture, and 0.6 candidate derivation.
+- [`MIGRATION.md`](MIGRATION.md) records the standalone extraction provenance.
 
-## 8. Build and verification entry points
+## Build and verification entry points
 
-The local `Makefile` exposes version-specific targets. The repository root
-`Makefile` forwards the most important checks under names such as:
+From the repository root, the main checks are:
 
-- `ravel-test`;
-- `ravel-training-check`;
-- `ravel-unified-check`;
-- `ravel-0.4-check`; and
-- `ravel-0.5-check`.
+- `make test`
+- `make training-check`
+- `make unified-check`
+- `make 0.4-check`
+- `make 0.5-check`
 
-Use verification targets before any target that rewrites evidence.
+Additional compiler-matrix, sanitizer, runtime, checkpoint, lineage, negative,
+and mutation targets remain available in the root Makefile.
 
-## 9. Where new work belongs
+## Placement rule
 
-- Cross-version explanation or navigation: `docs/`.
-- Evaluator, digest, mutation, or derivation script: `tools/`.
-- New epoch source, contract, preregistration, and evidence: use a clearly
-  versioned identity and document the complete lifecycle before adding files.
-- Historical frozen artifacts: do not rename, regroup, or rewrite merely for
-  visual consistency.
+Cross-version explanation belongs under `docs/`; executable support tooling stays
+under `tools/`; version-bound material belongs under `ravel_versions/`. Physical
+moves of historical artifacts are acceptable only when their bytes and recorded
+logical identities remain intact. Recorded `FAIL`, `UNKNOWN`, and non-promotion
+outcomes are not rewritten.
diff --git a/docs/README.md b/docs/README.md
index 31953f2..d160e51 100644
--- a/docs/README.md
+++ b/docs/README.md
@@ -1,8 +1,8 @@
 # RAVEL documentation hub
 
-This directory is the human-navigation layer for the RAVEL case study. It does
-not replace versioned contracts, preregistrations, raw observations, manifests,
-or assurance records in the parent directory.
+This directory is the human-navigation layer for the standalone RAVEL project.
+It does not replace versioned contracts, preregistrations, raw observations,
+manifests, or assurance records under `../ravel_versions/`.
 
 ## Guides
 
@@ -33,6 +33,6 @@ claims.
 
 Add explanatory, cross-version, or navigational material here. Keep executable
 support scripts under `../tools/`. Keep version-bound contracts, source,
-preregistrations, observations, manifests, and assurance records in their
-existing versioned locations unless a new epoch explicitly defines a different
-layout and identity scheme.
+preregistrations, observations, manifests, and assurance records under
+`../ravel_versions/` unless a new epoch explicitly defines a different layout
+and identity scheme.
diff --git a/docs/VERSION_HISTORY.md b/docs/VERSION_HISTORY.md
index deea0e2..8104f41 100644
--- a/docs/VERSION_HISTORY.md
+++ b/docs/VERSION_HISTORY.md
@@ -10,7 +10,8 @@ actual contracts, observations, and dispositions.
 experts are provably unable to win, while falling back to the complete oracle
 otherwise?
 
-**Primary files:** `ravel.c`, `CONTRACT.md`, and `evidence.json`.
+**Primary files:** `ravel_versions/baseline/ravel.c`,
+`ravel_versions/baseline/CONTRACT.md`, and `ravel_versions/baseline/evidence.json`.
 
 The study generated 256 experts and retrieved 24 candidates per familiar query.
 Historical development observations reported zero mismatches, complete
@@ -25,8 +26,9 @@ production evidence.
 **Question:** Can routed assignments, unresolved error, bounded splits, and child
 lineage recursively build a more capable expert population?
 
-**Primary files:** `ravel_train.c`, `TRAINING_CONTRACT.md`, and the
-`training-*.json` records.
+**Primary files:** `ravel_versions/training/ravel_train.c`,
+`ravel_versions/training/TRAINING_CONTRACT.md`, and the
+`ravel_versions/training/training-*.json` records.
 
 The recursive 8-to-64 study historically reached the same reported holdout
 accuracy as the flat 64-expert comparison while using substantially fewer
@@ -43,10 +45,13 @@ representation, classification, action-conditioned prediction, transition
 memory, bounded planning, adaptation, retirement, lineage, and checkpoint
 identity?
 
-**Primary files:** `ravel_unified.c`, `ravel_unified/*.inc`,
-`UNIFIED_CONTRACT.md`, `unified-preregistration.json`,
-`unified-evidence.json`, `unified-threat-model.json`, and
-`unified-assurance-case.json`.
+**Primary files:** `ravel_versions/unified/ravel_unified.c`,
+`ravel_versions/unified/ravel_unified/*.inc`,
+`ravel_versions/unified/UNIFIED_CONTRACT.md`,
+`ravel_versions/unified/unified-preregistration.json`,
+`ravel_versions/unified/unified-evidence.json`,
+`ravel_versions/unified/unified-threat-model.json`, and
+`ravel_versions/unified/unified-assurance-case.json`.
 
 The synthetic world contained 64 states, four actions, eight labels, and
 8-dimensional observations. Historical development output reported strong base
@@ -71,15 +76,15 @@ without removing unfavorable cases?
 
 **Primary files:**
 
-- `ravel_0_4.c`;
-- `RAVEL_0_4_CONTRACT.md`;
-- `ravel-0.4-preregistration.json`;
-- `ravel-0.4-raw-observations.json`;
-- `ravel-0.4-trial-evidence.json`;
-- `ravel-0.4-negative-evidence.json`;
-- `ravel-0.4-source-manifest.json`;
-- `ravel-0.4-assurance-case.json`; and
-- `RAVEL_0_4_RESULTS.md`.
+- `ravel_versions/0.4/ravel_0_4.c`;
+- `ravel_versions/0.4/RAVEL_0_4_CONTRACT.md`;
+- `ravel_versions/0.4/ravel-0.4-preregistration.json`;
+- `ravel_versions/0.4/ravel-0.4-raw-observations.json`;
+- `ravel_versions/0.4/ravel-0.4-trial-evidence.json`;
+- `ravel_versions/0.4/ravel-0.4-negative-evidence.json`;
+- `ravel_versions/0.4/ravel-0.4-source-manifest.json`;
+- `ravel_versions/0.4/ravel-0.4-assurance-case.json`; and
+- `ravel_versions/0.4/RAVEL_0_4_RESULTS.md`.
 
 RAVEL 0.4 introduced disjoint training, adaptation, holdout, retention, and
 planning partitions; canonical checkpoint encoding; complete restored-behavior
@@ -98,18 +103,18 @@ the most important 0.4 defects without weakening the frozen evidence boundary?
 
 **Primary files:**
 
-- `ravel_0_5.c`;
-- `RAVEL_0_5_CONTRACT.md`;
-- `ravel-0.5-preregistration.json`;
+- `ravel_versions/0.5/ravel_0_5.c`;
+- `ravel_versions/0.5/RAVEL_0_5_CONTRACT.md`;
+- `ravel_versions/0.5/ravel-0.5-preregistration.json`;
 - `tools/ravel_0_5_evaluator.py`;
 - `tools/ravel_0_5_evidence.py`;
-- `ravel-0.5-raw-observations.json`;
-- `ravel-0.5-trial-evidence.json`;
-- `ravel-0.5-negative-evidence.json`;
-- `ravel-0.5-source-and-execution-manifest.json`;
-- `ravel-0.5-assurance-case.json`;
-- `RAVEL_0_5_RESULTS.md`; and
-- `RAVEL_0_5_POSTMORTEM.md`.
+- `ravel_versions/0.5/ravel-0.5-raw-observations.json`;
+- `ravel_versions/0.5/ravel-0.5-trial-evidence.json`;
+- `ravel_versions/0.5/ravel-0.5-negative-evidence.json`;
+- `ravel_versions/0.5/ravel-0.5-source-and-execution-manifest.json`;
+- `ravel_versions/0.5/ravel-0.5-assurance-case.json`;
+- `ravel_versions/0.5/RAVEL_0_5_RESULTS.md`; and
+- `ravel_versions/0.5/RAVEL_0_5_POSTMORTEM.md`.
 
 Mechanism changes included stratified replay, anchored base experts,
 objective-tested lifecycle changes, normalized residual channels,
@@ -136,14 +141,14 @@ separated development and selection lifecycle?
 
 **Primary files:**
 
-- `RAVEL_0_6_SCOPE.md`;
-- `RAVEL_0_6_PREREGISTRATION.md`;
-- `ravel-0.6-preregistration.json`;
-- `ravel-0.6-threat-model.json`;
-- `ravel-0.6-development-record.json`;
-- `ravel-0.6-limitations.md`;
+- `ravel_versions/0.6/RAVEL_0_6_SCOPE.md`;
+- `ravel_versions/0.6/RAVEL_0_6_PREREGISTRATION.md`;
+- `ravel_versions/0.6/ravel-0.6-preregistration.json`;
+- `ravel_versions/0.6/ravel-0.6-threat-model.json`;
+- `ravel_versions/0.6/ravel-0.6-development-record.json`;
+- `ravel_versions/0.6/ravel-0.6-limitations.md`;
 - `tools/ravel_0_6_seed_candidate.py`; and
-- `RAVEL_0_6_NEXT_STEPS.md`.
+- `ravel_versions/0.6/RAVEL_0_6_NEXT_STEPS.md`.
 
 The epoch was preregistered before implementation. Development, selection,
 retention, transition-retention, planning, and future-final partitions have
diff --git a/RAVEL_0_4_CONTRACT.md b/ravel_versions/0.4/RAVEL_0_4_CONTRACT.md
similarity index 100%
rename from RAVEL_0_4_CONTRACT.md
rename to ravel_versions/0.4/RAVEL_0_4_CONTRACT.md
diff --git a/RAVEL_0_4_RESULTS.md b/ravel_versions/0.4/RAVEL_0_4_RESULTS.md
similarity index 100%
rename from RAVEL_0_4_RESULTS.md
rename to ravel_versions/0.4/RAVEL_0_4_RESULTS.md
diff --git a/RAVEL_0_4_SCOPE.md b/ravel_versions/0.4/RAVEL_0_4_SCOPE.md
similarity index 100%
rename from RAVEL_0_4_SCOPE.md
rename to ravel_versions/0.4/RAVEL_0_4_SCOPE.md
diff --git a/ravel_versions/0.4/path_compat.py b/ravel_versions/0.4/path_compat.py
new file mode 100644
index 0000000..e89d3bc
--- /dev/null
+++ b/ravel_versions/0.4/path_compat.py
@@ -0,0 +1,64 @@
+"""Path adapter for the preserved 0.4 manifest protocol."""
+
+from __future__ import annotations
+
+import hashlib
+import struct
+from pathlib import Path
+from typing import Any
+
+
+def physical_path(logical: str, case_root: Path, repository_root: Path) -> Path | None:
+    candidate = case_root / logical
+    if candidate.is_file():
+        return candidate
+    if logical.startswith("tools/"):
+        candidate = repository_root / logical
+        return candidate if candidate.is_file() else None
+    return None
+
+
+def build_manifest(
+    spec_path: Path, case_root: Path, repository_root: Path, digest_module: Any
+) -> dict[str, Any]:
+    spec = digest_module.load_json(spec_path)
+    digest_module.validate_spec(spec)
+    entries: list[dict[str, Any]] = []
+    for item in spec["ordered_files"]:
+        logical = item["path"]
+        absolute = physical_path(logical, case_root, repository_root)
+        if absolute is None:
+            raise digest_module.ManifestError(f"listed source file is missing: {logical}")
+        content = absolute.read_bytes()
+        entries.append(
+            {
+                "order": len(entries),
+                "role": item["role"],
+                "path": logical,
+                "bytes": len(content),
+                "sha256": hashlib.sha256(content).hexdigest(),
+            }
+        )
+    framed = hashlib.sha256()
+    for entry in entries:
+        logical_bytes = entry["path"].encode("utf-8")
+        content_path = physical_path(entry["path"], case_root, repository_root)
+        assert content_path is not None
+        content = content_path.read_bytes()
+        framed.update(struct.pack(">I", len(logical_bytes)))
+        framed.update(logical_bytes)
+        framed.update(struct.pack(">Q", len(content)))
+        framed.update(content)
+    return {
+        "schema": "ravel-source-manifest/0.4",
+        "entrypoint": spec["entrypoint"],
+        "generated_execution_shards": spec["generated_execution_shards"],
+        "generator_source": None,
+        "source_provenance": spec["source_provenance"],
+        "evidence_schema_versions": spec["evidence_schema_versions"],
+        "digest_algorithm": spec["digest_algorithm"],
+        "digest_procedure": spec["digest_procedure"],
+        "ordered_files": entries,
+        "source_digest": framed.hexdigest(),
+        "unexpected_execution_shards": [],
+    }
diff --git a/ravel-0.4-assurance-case.json b/ravel_versions/0.4/ravel-0.4-assurance-case.json
similarity index 100%
rename from ravel-0.4-assurance-case.json
rename to ravel_versions/0.4/ravel-0.4-assurance-case.json
diff --git a/ravel-0.4-limitations.md b/ravel_versions/0.4/ravel-0.4-limitations.md
similarity index 100%
rename from ravel-0.4-limitations.md
rename to ravel_versions/0.4/ravel-0.4-limitations.md
diff --git a/ravel-0.4-negative-evidence.json b/ravel_versions/0.4/ravel-0.4-negative-evidence.json
similarity index 100%
rename from ravel-0.4-negative-evidence.json
rename to ravel_versions/0.4/ravel-0.4-negative-evidence.json
diff --git a/ravel-0.4-preregistration.json b/ravel_versions/0.4/ravel-0.4-preregistration.json
similarity index 100%
rename from ravel-0.4-preregistration.json
rename to ravel_versions/0.4/ravel-0.4-preregistration.json
diff --git a/ravel-0.4-raw-observations.json b/ravel_versions/0.4/ravel-0.4-raw-observations.json
similarity index 100%
rename from ravel-0.4-raw-observations.json
rename to ravel_versions/0.4/ravel-0.4-raw-observations.json
diff --git a/ravel-0.4-runtime-observations.json b/ravel_versions/0.4/ravel-0.4-runtime-observations.json
similarity index 100%
rename from ravel-0.4-runtime-observations.json
rename to ravel_versions/0.4/ravel-0.4-runtime-observations.json
diff --git a/ravel-0.4-source-manifest-spec.json b/ravel_versions/0.4/ravel-0.4-source-manifest-spec.json
similarity index 100%
rename from ravel-0.4-source-manifest-spec.json
rename to ravel_versions/0.4/ravel-0.4-source-manifest-spec.json
diff --git a/ravel-0.4-source-manifest.json b/ravel_versions/0.4/ravel-0.4-source-manifest.json
similarity index 100%
rename from ravel-0.4-source-manifest.json
rename to ravel_versions/0.4/ravel-0.4-source-manifest.json
diff --git a/ravel-0.4-threat-model.json b/ravel_versions/0.4/ravel-0.4-threat-model.json
similarity index 100%
rename from ravel-0.4-threat-model.json
rename to ravel_versions/0.4/ravel-0.4-threat-model.json
diff --git a/ravel-0.4-trial-evidence.json b/ravel_versions/0.4/ravel-0.4-trial-evidence.json
similarity index 100%
rename from ravel-0.4-trial-evidence.json
rename to ravel_versions/0.4/ravel-0.4-trial-evidence.json
diff --git a/ravel_0_4.c b/ravel_versions/0.4/ravel_0_4.c
similarity index 100%
rename from ravel_0_4.c
rename to ravel_versions/0.4/ravel_0_4.c
diff --git a/ravel_versions/0.4/run_evidence.py b/ravel_versions/0.4/run_evidence.py
new file mode 100644
index 0000000..283f87e
--- /dev/null
+++ b/ravel_versions/0.4/run_evidence.py
@@ -0,0 +1,36 @@
+#!/usr/bin/env python3
+"""Run the preserved 0.4 evidence utility against its relocated case root."""
+
+from __future__ import annotations
+
+import sys
+from pathlib import Path
+
+CASE_ROOT = Path(__file__).resolve().parent
+REPOSITORY_ROOT = CASE_ROOT.parents[1]
+sys.path.insert(0, str(REPOSITORY_ROOT / "tools"))
+
+import ravel_source_digest as digest  # noqa: E402
+import ravel_0_4_evidence as evidence  # noqa: E402
+from path_compat import build_manifest as compat_build_manifest  # noqa: E402
+
+digest.CASE_ROOT = CASE_ROOT
+digest.build_manifest = lambda spec_path: compat_build_manifest(
+    spec_path, CASE_ROOT, REPOSITORY_ROOT, digest
+)
+evidence.CASE_ROOT = CASE_ROOT
+evidence.build_manifest = digest.build_manifest
+for name in (
+    "PREREGISTRATION",
+    "MANIFEST_SPEC",
+    "RAW_EVIDENCE",
+    "TRIAL_EVIDENCE",
+    "NEGATIVE_EVIDENCE",
+    "SOURCE_MANIFEST",
+    "ASSURANCE",
+    "RESULTS_DOC",
+    "RUNTIME_EVIDENCE",
+):
+    setattr(evidence, name, CASE_ROOT / getattr(evidence, name).name)
+
+raise SystemExit(evidence.main())
diff --git a/ravel_versions/0.4/run_source_digest.py b/ravel_versions/0.4/run_source_digest.py
new file mode 100644
index 0000000..e1f84a9
--- /dev/null
+++ b/ravel_versions/0.4/run_source_digest.py
@@ -0,0 +1,21 @@
+#!/usr/bin/env python3
+"""Run the preserved 0.4 digest utility against its relocated case root."""
+
+from __future__ import annotations
+
+import sys
+from pathlib import Path
+
+CASE_ROOT = Path(__file__).resolve().parent
+REPOSITORY_ROOT = CASE_ROOT.parents[1]
+sys.path.insert(0, str(REPOSITORY_ROOT / "tools"))
+
+import ravel_source_digest as digest  # noqa: E402
+from path_compat import build_manifest as compat_build_manifest  # noqa: E402
+
+digest.CASE_ROOT = CASE_ROOT
+digest.build_manifest = lambda spec_path: compat_build_manifest(
+    spec_path, CASE_ROOT, REPOSITORY_ROOT, digest
+)
+
+raise SystemExit(digest.main())
diff --git a/ravel_versions/0.5/Makefile b/ravel_versions/0.5/Makefile
new file mode 100644
index 0000000..5dcc289
--- /dev/null
+++ b/ravel_versions/0.5/Makefile
@@ -0,0 +1,218 @@
+CC ?= cc
+SAN_CC ?= clang
+CFLAGS ?= -std=c11 -O3 -Wall -Wextra -Werror -pedantic
+LDLIBS ?= -lm
+
+.PHONY: test evidence training-test training-evidence training-check unified-test unified-evidence unified-check 0.4-evidence 0.4-check 0.4-manifest-negative-test 0.4-checkpoint-test 0.4-lineage-test 0.4-negative-test 0.4-compiler-matrix 0.4-sanitizers 0.4-runtime 0.5-test 0.5-evidence 0.5-check 0.5-development-gates 0.5-negative-test 0.5-manifest-negative-test 0.5-compiler-matrix 0.5-sanitizers 0.5-runtime 0.5-clean all clean
+
+test: ravel
+	./ravel >/dev/null
+
+evidence: ravel
+	@tmp=$$(mktemp); \
+	trap 'rm -f "$$tmp"' EXIT; \
+	if ./ravel > "$$tmp"; then \
+		mv "$$tmp" evidence-actual.json; \
+	else \
+		cp "$$tmp" evidence-actual.json; \
+		exit 1; \
+	fi
+
+training-test: ravel_train
+	./ravel_train >/dev/null
+
+training-evidence: ravel_train
+	@tmp=$$(mktemp); \
+	trap 'rm -f "$$tmp"' EXIT; \
+	./ravel_train > "$$tmp"; \
+	mv "$$tmp" training-evidence.json
+
+training-check: ravel_train
+	@tmp=$$(mktemp); \
+	trap 'rm -f "$$tmp"' EXIT; \
+	./ravel_train > "$$tmp"; \
+	diff -u training-evidence.json "$$tmp"
+
+unified-test: ravel_unified_bin
+	./ravel_unified_bin >/dev/null
+
+unified-evidence: ravel_unified_bin
+	@tmp=$$(mktemp); \
+	trap 'rm -f "$$tmp"' EXIT; \
+	./ravel_unified_bin > "$$tmp"; \
+	mv "$$tmp" unified-evidence.json
+
+unified-check: ravel_unified_bin
+	@tmp=$$(mktemp); \
+	trap 'rm -f "$$tmp"' EXIT; \
+	if ./ravel_unified_bin > "$$tmp" && diff -u unified-evidence.json "$$tmp"; then \
+		rm -f unified-actual.json; \
+	else \
+		cp "$$tmp" unified-actual.json; \
+		exit 1; \
+	fi
+
+0.4-evidence: ravel_0_4_bin
+	python3 tools/ravel_0_4_evidence.py generate --binary ./ravel_0_4_bin
+
+0.4-check: ravel_0_4_bin
+	python3 tools/ravel_0_4_evidence.py verify --binary ./ravel_0_4_bin --diagnostics-dir diagnostics
+	python3 tools/ravel_source_digest.py verify \
+		--spec ravel-0.4-source-manifest-spec.json \
+		--manifest ravel-0.4-source-manifest.json \
+		--assurance ravel-0.4-assurance-case.json
+
+0.4-manifest-negative-test:
+	@tmp=$$(mktemp -d); \
+	trap 'rm -rf "$$tmp"' EXIT; \
+	cp -a . "$$tmp/ravel"; \
+	cd "$$tmp/ravel"; \
+	verify='python3 tools/ravel_source_digest.py verify --spec ravel-0.4-source-manifest-spec.json --manifest ravel-0.4-source-manifest.json --assurance ravel-0.4-assurance-case.json'; \
+	$$verify >/dev/null; \
+	cp RAVEL_0_4_CONTRACT.md contract.saved; \
+	printf '\nmutation\n' >> RAVEL_0_4_CONTRACT.md; \
+	if $$verify >/dev/null 2>&1; then exit 1; fi; \
+	mv contract.saved RAVEL_0_4_CONTRACT.md; \
+	cp ravel-0.4-source-manifest.json manifest.saved; \
+	python3 -c 'import json; p="ravel-0.4-source-manifest.json"; r=json.load(open(p)); r["ordered_files"].pop(); json.dump(r,open(p,"w"))'; \
+	if $$verify >/dev/null 2>&1; then exit 1; fi; \
+	cp manifest.saved ravel-0.4-source-manifest.json; \
+	python3 -c 'import json; p="ravel-0.4-source-manifest.json"; r=json.load(open(p)); r["ordered_files"][0],r["ordered_files"][1]=r["ordered_files"][1],r["ordered_files"][0]; json.dump(r,open(p,"w"))'; \
+	if $$verify >/dev/null 2>&1; then exit 1; fi; \
+	cp manifest.saved ravel-0.4-source-manifest.json; \
+	mkdir -p ravel_0_4; \
+	printf 'unexpected\n' > ravel_0_4/unexpected.inc; \
+	if $$verify >/dev/null 2>&1; then exit 1; fi; \
+	rm -rf ravel_0_4; \
+	cp ravel-0.4-assurance-case.json assurance.saved; \
+	python3 -c 'import json; p="ravel-0.4-assurance-case.json"; r=json.load(open(p)); r["implementation"]["source_digest"]="0"*64; json.dump(r,open(p,"w"))'; \
+	if $$verify >/dev/null 2>&1; then exit 1; fi; \
+	mv assurance.saved ravel-0.4-assurance-case.json
+
+0.4-checkpoint-test: ravel_0_4_bin
+	@tmp=$$(mktemp); \
+	trap 'rm -f "$$tmp"' EXIT; \
+	./ravel_0_4_bin > "$$tmp"; \
+	python3 -c 'import json,sys; r=json.load(open(sys.argv[1])); assert all(t["checkpoint_verification"]["complete_behavior_match"] and all(t["checkpoint_verification"]["mutations"].values()) for t in r["trials"])' "$$tmp"
+
+0.4-lineage-test: ravel_0_4_bin
+	@tmp=$$(mktemp); \
+	trap 'rm -f "$$tmp"' EXIT; \
+	./ravel_0_4_bin > "$$tmp"; \
+	python3 -c 'import json,sys; r=json.load(open(sys.argv[1])); assert all(all(t["lineage_invariants"].values()) for t in r["trials"])' "$$tmp"
+
+0.4-negative-test: ravel_0_4_bin
+	@tmp=$$(mktemp); \
+	trap 'rm -f "$$tmp"' EXIT; \
+	./ravel_0_4_bin > "$$tmp"; \
+	python3 -c 'import json,sys; r=json.load(open(sys.argv[1])); assert all(v["pass"] for v in r["negative_tests"].values())' "$$tmp"
+
+0.4-compiler-matrix:
+	@set -eu; \
+	for compiler in gcc clang; do \
+		if command -v "$$compiler" >/dev/null 2>&1; then \
+			for optimization in 0 3; do \
+				binary=$$(mktemp); output=$$(mktemp); \
+				"$$compiler" -std=c11 "-O$$optimization" -Wall -Wextra -Werror -pedantic ravel_0_4.c -lm -o "$$binary"; \
+				"$$binary" > "$$output"; \
+				diff -u ravel-0.4-raw-observations.json "$$output"; \
+				rm -f "$$binary" "$$output"; \
+			done; \
+		fi; \
+	done
+
+0.4-sanitizers:
+	@set -eu; \
+	command -v "$(SAN_CC)" >/dev/null 2>&1 || { echo "sanitizer compiler unavailable: $(SAN_CC)" >&2; exit 1; }; \
+	binary=$$(mktemp); output=$$(mktemp); \
+	trap 'rm -f "$$binary" "$$output"' EXIT; \
+	$(SAN_CC) -std=c11 -O1 -g -Wall -Wextra -Werror -pedantic \
+		-fsanitize=address,undefined -fno-omit-frame-pointer \
+		ravel_0_4.c -lm -o "$$binary"; \
+	ASAN_OPTIONS=detect_leaks=1 UBSAN_OPTIONS=halt_on_error=1 "$$binary" > "$$output"; \
+	diff -u ravel-0.4-raw-observations.json "$$output"
+
+0.4-runtime: ravel_0_4_bin
+	python3 tools/ravel_0_4_evidence.py runtime --binary ./ravel_0_4_bin --runs 3
+
+0.5-test: ravel_0_5_bin
+	@tmp=$$(mktemp); \
+	trap 'rm -f "$$tmp"' EXIT; \
+	./ravel_0_5_bin --self-test > "$$tmp"; \
+	python3 -c 'import json,sys; r=json.load(open(sys.argv[1])); assert r["schema"] == "ravel-self-test-observations/0.5"; assert all(v["observed"] for v in r["fixtures"].values())' "$$tmp"
+
+0.5-evidence: ravel_0_5_bin
+	python3 tools/ravel_0_5_evidence.py generate --binary ./ravel_0_5_bin
+
+0.5-check: ravel_0_5_bin
+	python3 tools/ravel_0_5_evidence.py verify --binary ./ravel_0_5_bin --diagnostics-dir diagnostics-0.5
+	python3 tools/ravel_0_5_source_digest.py verify \
+		--spec ravel-0.5-source-manifest-spec.json \
+		--manifest ravel-0.5-source-and-execution-manifest.json \
+		--assurance ravel-0.5-assurance-case.json
+
+0.5-development-gates:
+	python3 tools/ravel_0_5_evidence.py development-gates
+
+0.5-negative-test: ravel_0_5_bin
+	$(MAKE) 0.5-test
+	python3 tools/ravel_0_5_evidence.py mutation-tests
+	python3 -c 'import json; r=json.load(open("ravel-0.5-negative-evidence.json")); assert r["all_negative_tests_pass"]; assert len(r["tests"]) == len(set(r["tests"]))'
+
+0.5-manifest-negative-test:
+	python3 tools/ravel_0_5_evidence.py manifest-negative-tests
+
+0.5-compiler-matrix:
+	@set -eu; \
+	for compiler in gcc clang; do \
+		if command -v "$$compiler" >/dev/null 2>&1; then \
+			for optimization in 0 3; do \
+				binary=$$(mktemp); \
+				trap 'rm -f "$$binary"' EXIT; \
+				"$$compiler" -std=c11 "-O$$optimization" -Wall -Wextra -Werror -pedantic ravel_0_5.c -lm -o "$$binary"; \
+				python3 tools/ravel_0_5_evidence.py verify --binary "$$binary" --diagnostics-dir diagnostics-0.5; \
+				rm -f "$$binary"; \
+				trap - EXIT; \
+			done; \
+		fi; \
+	done
+
+0.5-sanitizers:
+	@set -eu; \
+	command -v "$(SAN_CC)" >/dev/null 2>&1 || { echo "sanitizer compiler unavailable: $(SAN_CC)" >&2; exit 1; }; \
+	binary=$$(mktemp); \
+	trap 'rm -f "$$binary"' EXIT; \
+	$(SAN_CC) -std=c11 -O1 -g -Wall -Wextra -Werror -pedantic \
+		-fsanitize=address,undefined -fno-omit-frame-pointer \
+		ravel_0_5.c -lm -o "$$binary"; \
+	ASAN_OPTIONS=detect_leaks=1 UBSAN_OPTIONS=halt_on_error=1 \
+		python3 tools/ravel_0_5_evidence.py verify --binary "$$binary" --diagnostics-dir diagnostics-0.5
+
+0.5-runtime: ravel_0_5_bin
+	python3 tools/ravel_0_5_evidence.py runtime --binary ./ravel_0_5_bin --runs 3
+
+0.5-clean:
+	rm -f ravel_0_5_bin
+	rm -rf diagnostics-0.5
+
+all: test training-check unified-check 0.4-check 0.5-check
+
+ravel: ravel.c
+	$(CC) $(CFLAGS) $< -o $@
+
+ravel_train: ravel_train.c
+	$(CC) $(CFLAGS) $< $(LDLIBS) -o $@
+
+ravel_unified_bin: ravel_unified.c ravel_unified/00_core.inc ravel_unified/10_route.inc ravel_unified/20_train.inc ravel_unified/30_eval.inc
+	$(CC) $(CFLAGS) ravel_unified.c $(LDLIBS) -o $@
+
+ravel_0_4_bin: ravel_0_4.c
+	$(CC) $(CFLAGS) ravel_0_4.c $(LDLIBS) -o $@
+
+ravel_0_5_bin: ravel_0_5.c
+	$(CC) $(CFLAGS) ravel_0_5.c $(LDLIBS) -o $@
+
+clean:
+	rm -f ravel ravel_train ravel_unified_bin ravel_0_4_bin ravel_0_5_bin
+	rm -f evidence-actual.json unified-actual.json ravel-unified-checkpoint.bin ravel-0.4-checkpoint.bin
+	rm -rf diagnostics
diff --git a/RAVEL_0_5_CONTRACT.md b/ravel_versions/0.5/RAVEL_0_5_CONTRACT.md
similarity index 100%
rename from RAVEL_0_5_CONTRACT.md
rename to ravel_versions/0.5/RAVEL_0_5_CONTRACT.md
diff --git a/RAVEL_0_5_POSTMORTEM.md b/ravel_versions/0.5/RAVEL_0_5_POSTMORTEM.md
similarity index 100%
rename from RAVEL_0_5_POSTMORTEM.md
rename to ravel_versions/0.5/RAVEL_0_5_POSTMORTEM.md
diff --git a/RAVEL_0_5_RESULTS.md b/ravel_versions/0.5/RAVEL_0_5_RESULTS.md
similarity index 100%
rename from RAVEL_0_5_RESULTS.md
rename to ravel_versions/0.5/RAVEL_0_5_RESULTS.md
diff --git a/RAVEL_0_5_SCOPE.md b/ravel_versions/0.5/RAVEL_0_5_SCOPE.md
similarity index 100%
rename from RAVEL_0_5_SCOPE.md
rename to ravel_versions/0.5/RAVEL_0_5_SCOPE.md
diff --git a/ravel-0.5-assurance-case.json b/ravel_versions/0.5/ravel-0.5-assurance-case.json
similarity index 100%
rename from ravel-0.5-assurance-case.json
rename to ravel_versions/0.5/ravel-0.5-assurance-case.json
diff --git a/ravel-0.5-development-corpus.json b/ravel_versions/0.5/ravel-0.5-development-corpus.json
similarity index 100%
rename from ravel-0.5-development-corpus.json
rename to ravel_versions/0.5/ravel-0.5-development-corpus.json
diff --git a/ravel-0.5-limitations.md b/ravel_versions/0.5/ravel-0.5-limitations.md
similarity index 100%
rename from ravel-0.5-limitations.md
rename to ravel_versions/0.5/ravel-0.5-limitations.md
diff --git a/ravel-0.5-negative-evidence.json b/ravel_versions/0.5/ravel-0.5-negative-evidence.json
similarity index 100%
rename from ravel-0.5-negative-evidence.json
rename to ravel_versions/0.5/ravel-0.5-negative-evidence.json
diff --git a/ravel-0.5-preregistration.json b/ravel_versions/0.5/ravel-0.5-preregistration.json
similarity index 100%
rename from ravel-0.5-preregistration.json
rename to ravel_versions/0.5/ravel-0.5-preregistration.json
diff --git a/ravel-0.5-raw-observations.json b/ravel_versions/0.5/ravel-0.5-raw-observations.json
similarity index 100%
rename from ravel-0.5-raw-observations.json
rename to ravel_versions/0.5/ravel-0.5-raw-observations.json
diff --git a/ravel-0.5-runtime-observations.json b/ravel_versions/0.5/ravel-0.5-runtime-observations.json
similarity index 100%
rename from ravel-0.5-runtime-observations.json
rename to ravel_versions/0.5/ravel-0.5-runtime-observations.json
diff --git a/ravel-0.5-source-and-execution-manifest.json b/ravel_versions/0.5/ravel-0.5-source-and-execution-manifest.json
similarity index 100%
rename from ravel-0.5-source-and-execution-manifest.json
rename to ravel_versions/0.5/ravel-0.5-source-and-execution-manifest.json
diff --git a/ravel-0.5-source-manifest-spec.json b/ravel_versions/0.5/ravel-0.5-source-manifest-spec.json
similarity index 100%
rename from ravel-0.5-source-manifest-spec.json
rename to ravel_versions/0.5/ravel-0.5-source-manifest-spec.json
diff --git a/ravel-0.5-threat-model.json b/ravel_versions/0.5/ravel-0.5-threat-model.json
similarity index 100%
rename from ravel-0.5-threat-model.json
rename to ravel_versions/0.5/ravel-0.5-threat-model.json
diff --git a/ravel-0.5-trial-evidence.json b/ravel_versions/0.5/ravel-0.5-trial-evidence.json
similarity index 100%
rename from ravel-0.5-trial-evidence.json
rename to ravel_versions/0.5/ravel-0.5-trial-evidence.json
diff --git a/ravel_0_5.c b/ravel_versions/0.5/ravel_0_5.c
similarity index 100%
rename from ravel_0_5.c
rename to ravel_versions/0.5/ravel_0_5.c
diff --git a/ravel_versions/0.5/run_evidence.py b/ravel_versions/0.5/run_evidence.py
new file mode 100644
index 0000000..0b60516
--- /dev/null
+++ b/ravel_versions/0.5/run_evidence.py
@@ -0,0 +1,144 @@
+#!/usr/bin/env python3
+"""Run preserved 0.5 tooling with historical logical-path compatibility."""
+
+from __future__ import annotations
+
+import hashlib
+import struct
+import sys
+from pathlib import Path
+from typing import Any
+
+CASE_ROOT = Path(__file__).resolve().parent
+REPOSITORY_ROOT = CASE_ROOT.parents[1]
+sys.path.insert(0, str(REPOSITORY_ROOT / "tools"))
+
+import ravel_0_5_evidence as evidence  # noqa: E402
+import ravel_0_5_source_digest as source_digest  # noqa: E402
+
+source_digest.CASE_ROOT = CASE_ROOT
+source_digest.REPOSITORY_ROOT = REPOSITORY_ROOT
+evidence.CASE_ROOT = CASE_ROOT
+evidence.TOOL_ROOT = REPOSITORY_ROOT / "tools"
+for name in (
+    "PREREGISTRATION",
+    "MANIFEST_SPEC",
+    "RAW",
+    "TRIAL",
+    "NEGATIVE",
+    "MANIFEST",
+    "ASSURANCE",
+    "RESULTS",
+    "RUNTIME",
+):
+    setattr(evidence, name, CASE_ROOT / getattr(evidence, name).name)
+evidence.PACKAGE_PATHS = (
+    evidence.RAW,
+    evidence.TRIAL,
+    evidence.NEGATIVE,
+    evidence.MANIFEST,
+    evidence.ASSURANCE,
+    evidence.RESULTS,
+)
+
+
+def physical_path(logical: str, repository_root: Path) -> Path | None:
+    """Resolve a historical manifest path without changing its logical spelling."""
+
+    if logical == "Makefile" and repository_root == REPOSITORY_ROOT:
+        return None
+    direct = repository_root / logical
+    if direct.is_file():
+        return direct
+    prefix = "case-studies/ravel/"
+    if logical.startswith(prefix):
+        relative = logical.removeprefix(prefix)
+        candidate = (
+            REPOSITORY_ROOT / "tools" / relative.removeprefix("tools/")
+            if relative.startswith("tools/")
+            else CASE_ROOT / relative
+        )
+        return candidate if candidate.is_file() else None
+    return direct if direct.is_file() else None
+
+
+def compat_build_manifest(
+    spec_path: Path, repository_root: Path | None = None
+) -> dict[str, Any]:
+    root = REPOSITORY_ROOT if repository_root is None else repository_root
+    spec = source_digest.load_json(spec_path)
+    source_digest.validate_spec(spec)
+    declared = set(spec["generated_execution_shards"]) | set(
+        spec["maintained_execution_sources"]
+    )
+    discovered: set[str] = set()
+    for pattern in spec.get("execution_source_discovery_globs", []):
+        prefix = "case-studies/ravel/"
+        if pattern.startswith(prefix):
+            for path in CASE_ROOT.glob(pattern.removeprefix(prefix)):
+                if path.is_file():
+                    discovered.add(prefix + path.relative_to(CASE_ROOT).as_posix())
+        else:
+            for path in root.glob(pattern):
+                if path.is_file():
+                    discovered.add(path.relative_to(root).as_posix())
+    unexpected = sorted(discovered - declared)
+    omitted = sorted(declared - discovered)
+    if unexpected:
+        raise source_digest.ManifestError(
+            f"unexpected execution shard outside manifest: {unexpected}"
+        )
+    if omitted:
+        raise source_digest.ManifestError(
+            f"declared execution shard is missing: {omitted}"
+        )
+
+    entries: list[dict[str, Any]] = []
+    for item in spec["ordered_files"]:
+        logical = item["path"]
+        absolute = physical_path(logical, root)
+        if absolute is None:
+            raise source_digest.ManifestError(
+                f"listed source file is missing: {logical}"
+            )
+        content = absolute.read_bytes()
+        entries.append(
+            {
+                "order": len(entries),
+                "role": item["role"],
+                "path": logical,
+                "bytes": len(content),
+                "sha256": hashlib.sha256(content).hexdigest(),
+            }
+        )
+    digest = hashlib.sha256()
+    for entry in entries:
+        logical_bytes = entry["path"].encode("utf-8")
+        content_path = physical_path(entry["path"], root)
+        assert content_path is not None
+        content = content_path.read_bytes()
+        digest.update(struct.pack(">I", len(logical_bytes)))
+        digest.update(logical_bytes)
+        digest.update(struct.pack(">Q", len(content)))
+        digest.update(content)
+    return {
+        "schema": "ravel-source-and-execution-manifest/0.5",
+        "entrypoint": spec["entrypoint"],
+        "maintained_execution_sources": spec["maintained_execution_sources"],
+        "generated_execution_shards": spec["generated_execution_shards"],
+        "generator_source": None,
+        "source_provenance": spec["source_provenance"],
+        "build_configuration": spec["build_configuration"],
+        "checkpoint_schema": spec["checkpoint_schema"],
+        "evidence_schema_versions": spec["evidence_schema_versions"],
+        "digest_algorithm": spec["digest_algorithm"],
+        "digest_procedure": spec["digest_procedure"],
+        "ordered_files": entries,
+        "source_digest": digest.hexdigest(),
+        "unexpected_execution_shards": [],
+    }
+
+
+evidence.build_manifest = compat_build_manifest
+
+raise SystemExit(evidence.main())
diff --git a/RAVEL_0_6_NEXT_STEPS.md b/ravel_versions/0.6/RAVEL_0_6_NEXT_STEPS.md
similarity index 100%
rename from RAVEL_0_6_NEXT_STEPS.md
rename to ravel_versions/0.6/RAVEL_0_6_NEXT_STEPS.md
diff --git a/RAVEL_0_6_PREREGISTRATION.md b/ravel_versions/0.6/RAVEL_0_6_PREREGISTRATION.md
similarity index 100%
rename from RAVEL_0_6_PREREGISTRATION.md
rename to ravel_versions/0.6/RAVEL_0_6_PREREGISTRATION.md
diff --git a/RAVEL_0_6_SCOPE.md b/ravel_versions/0.6/RAVEL_0_6_SCOPE.md
similarity index 100%
rename from RAVEL_0_6_SCOPE.md
rename to ravel_versions/0.6/RAVEL_0_6_SCOPE.md
diff --git a/ravel-0.6-development-record.json b/ravel_versions/0.6/ravel-0.6-development-record.json
similarity index 100%
rename from ravel-0.6-development-record.json
rename to ravel_versions/0.6/ravel-0.6-development-record.json
diff --git a/ravel-0.6-limitations.md b/ravel_versions/0.6/ravel-0.6-limitations.md
similarity index 100%
rename from ravel-0.6-limitations.md
rename to ravel_versions/0.6/ravel-0.6-limitations.md
diff --git a/ravel-0.6-preregistration.json b/ravel_versions/0.6/ravel-0.6-preregistration.json
similarity index 100%
rename from ravel-0.6-preregistration.json
rename to ravel_versions/0.6/ravel-0.6-preregistration.json
diff --git a/ravel-0.6-preregistration.schema.json b/ravel_versions/0.6/ravel-0.6-preregistration.schema.json
similarity index 100%
rename from ravel-0.6-preregistration.schema.json
rename to ravel_versions/0.6/ravel-0.6-preregistration.schema.json
diff --git a/ravel-0.6-threat-model.json b/ravel_versions/0.6/ravel-0.6-threat-model.json
similarity index 100%
rename from ravel-0.6-threat-model.json
rename to ravel_versions/0.6/ravel-0.6-threat-model.json
diff --git a/CONTRACT.md b/ravel_versions/baseline/CONTRACT.md
similarity index 100%
rename from CONTRACT.md
rename to ravel_versions/baseline/CONTRACT.md
diff --git a/evidence.json b/ravel_versions/baseline/evidence.json
similarity index 100%
rename from evidence.json
rename to ravel_versions/baseline/evidence.json
diff --git a/ravel.c b/ravel_versions/baseline/ravel.c
similarity index 100%
rename from ravel.c
rename to ravel_versions/baseline/ravel.c
diff --git a/TRAINING_CONTRACT.md b/ravel_versions/training/TRAINING_CONTRACT.md
similarity index 100%
rename from TRAINING_CONTRACT.md
rename to ravel_versions/training/TRAINING_CONTRACT.md
diff --git a/ravel_train.c b/ravel_versions/training/ravel_train.c
similarity index 100%
rename from ravel_train.c
rename to ravel_versions/training/ravel_train.c
diff --git a/training-assurance-case.json b/ravel_versions/training/training-assurance-case.json
similarity index 100%
rename from training-assurance-case.json
rename to ravel_versions/training/training-assurance-case.json
diff --git a/training-evidence.json b/ravel_versions/training/training-evidence.json
similarity index 100%
rename from training-evidence.json
rename to ravel_versions/training/training-evidence.json
diff --git a/training-preregistration.json b/ravel_versions/training/training-preregistration.json
similarity index 100%
rename from training-preregistration.json
rename to ravel_versions/training/training-preregistration.json
diff --git a/training-threat-model.json b/ravel_versions/training/training-threat-model.json
similarity index 100%
rename from training-threat-model.json
rename to ravel_versions/training/training-threat-model.json
diff --git a/UNIFIED_CONTRACT.md b/ravel_versions/unified/UNIFIED_CONTRACT.md
similarity index 100%
rename from UNIFIED_CONTRACT.md
rename to ravel_versions/unified/UNIFIED_CONTRACT.md
diff --git a/ravel_unified.c b/ravel_versions/unified/ravel_unified.c
similarity index 100%
rename from ravel_unified.c
rename to ravel_versions/unified/ravel_unified.c
diff --git a/ravel_unified/00_core.inc b/ravel_versions/unified/ravel_unified/00_core.inc
similarity index 100%
rename from ravel_unified/00_core.inc
rename to ravel_versions/unified/ravel_unified/00_core.inc
diff --git a/ravel_unified/10_route.inc b/ravel_versions/unified/ravel_unified/10_route.inc
similarity index 100%
rename from ravel_unified/10_route.inc
rename to ravel_versions/unified/ravel_unified/10_route.inc
diff --git a/ravel_unified/20_train.inc b/ravel_versions/unified/ravel_unified/20_train.inc
similarity index 100%
rename from ravel_unified/20_train.inc
rename to ravel_versions/unified/ravel_unified/20_train.inc
diff --git a/ravel_unified/30_eval.inc b/ravel_versions/unified/ravel_unified/30_eval.inc
similarity index 100%
rename from ravel_unified/30_eval.inc
rename to ravel_versions/unified/ravel_unified/30_eval.inc
diff --git a/unified-assurance-case.json b/ravel_versions/unified/unified-assurance-case.json
similarity index 100%
rename from unified-assurance-case.json
rename to ravel_versions/unified/unified-assurance-case.json
diff --git a/unified-evidence.json b/ravel_versions/unified/unified-evidence.json
similarity index 100%
rename from unified-evidence.json
rename to ravel_versions/unified/unified-evidence.json
diff --git a/unified-preregistration.json b/ravel_versions/unified/unified-preregistration.json
similarity index 100%
rename from unified-preregistration.json
rename to ravel_versions/unified/unified-preregistration.json
diff --git a/unified-threat-model.json b/ravel_versions/unified/unified-threat-model.json
similarity index 100%
rename from unified-threat-model.json
rename to ravel_versions/unified/unified-threat-model.json
diff --git a/tools/README.md b/tools/README.md
index 4096709..ed95679 100644
--- a/tools/README.md
+++ b/tools/README.md
@@ -4,6 +4,13 @@ The scripts in this directory build, verify, mutate, digest, and summarize RAVEL
 evidence. They are support tools, not automatic sources of independent custody,
 organizational independence, or promotion authority.
 
+The preserved 0.4 and 0.5 modules retain their original case-root assumptions
+and bytes. Run `ravel_versions/0.4/run_evidence.py`,
+`ravel_versions/0.4/run_source_digest.py`, or
+`ravel_versions/0.5/run_evidence.py` through the root Makefile for the relocated
+layout; those small runners provide path compatibility without rewriting frozen
+modules or historical logical paths.
+
 ## Tool categories
 
 | Tool | Role |
@@ -89,7 +96,7 @@ separation alone is not organizational independence or protected evaluation.
 
 The current candidate-001 corrections expand planning traversal to all declared
 transition slots and remove inherited empirical support from adaptation births.
-See `../RAVEL_0_6_NEXT_STEPS.md` for the remaining lifecycle and evidence work.
+See `../ravel_versions/0.6/RAVEL_0_6_NEXT_STEPS.md` for the remaining lifecycle and evidence work.
 
 ## Adding or changing a tool
 
diff --git a/tools/__pycache__/ravel_0_5_evaluator.cpython-314.pyc b/tools/__pycache__/ravel_0_5_evaluator.cpython-314.pyc
deleted file mode 100644
index 4889457..0000000
Binary files a/tools/__pycache__/ravel_0_5_evaluator.cpython-314.pyc and /dev/null differ
diff --git a/tools/__pycache__/ravel_0_5_source_digest.cpython-314.pyc b/tools/__pycache__/ravel_0_5_source_digest.cpython-314.pyc
deleted file mode 100644
index aaa4211..0000000
Binary files a/tools/__pycache__/ravel_0_5_source_digest.cpython-314.pyc and /dev/null differ
diff --git a/tools/__pycache__/ravel_source_digest.cpython-314.pyc b/tools/__pycache__/ravel_source_digest.cpython-314.pyc
deleted file mode 100644
index 186851d..0000000
Binary files a/tools/__pycache__/ravel_source_digest.cpython-314.pyc and /dev/null differ
diff --git a/tools/ravel_0_6_seed_candidate.py b/tools/ravel_0_6_seed_candidate.py
index f0b25df..910efe6 100644
--- a/tools/ravel_0_6_seed_candidate.py
+++ b/tools/ravel_0_6_seed_candidate.py
@@ -22,7 +22,7 @@
 from pathlib import Path
 
 RAVEL_DIR = Path(__file__).resolve().parents[1]
-FROZEN_SOURCE = RAVEL_DIR / "ravel_0_5.c"
+FROZEN_SOURCE = RAVEL_DIR / "ravel_versions/0.5/ravel_0_5.c"
 FROZEN_SOURCE_SHA256 = "1a8466ea1805811873c461fb891aaeaec18f6c9e7491b5ea7bd09bf698be102d"
 
 OLD_SEED_FUNCTION = """\