Run integration through the worker launcher

ci/README.md

@@ -24,15 +24,15 @@ from):
    [`preprocess-require.awk`](preprocess-require.awk) rewrites each `require <ext>` into an
    explicit signed `INSTALL <ext> FROM {community,core}; LOAD <ext>;`. `require-env` and
    everything else pass through.
-5. **Run** — [`run-integration.sh`](run-integration.sh) stages the preprocessed tree, wires
-   `VGI_TEST_WORKER`/`VGI_SIMPLE_WRITABLE_WORKER`/`VGI_BAD_PROTOCOL_WORKER` at the three built
-   binaries, `FORCE INSTALL`s the vgi extension (so the run uses what users can install today),
-   then runs the suite in a single `haybarn-unittest` invocation.
+5. **Run** — [`run-integration.sh`](run-integration.sh) stages the preprocessed tree and places
+   the main worker behind DuckDB's `launch:` AF_UNIX pool, so repeated ATTACHes reuse one warm
+   .NET process. The small stateful and incompatible-protocol fixture workers remain isolated
+   subprocesses. The harness `FORCE INSTALL`s the vgi extension (so the run uses what users can
+   install today), then runs the suite in a single `haybarn-unittest` invocation.
 
 ## Scope of this version
 
-This is deliberately a **single lane** (the default subprocess transport, matching
-`scripts/run_tests.sh`'s `SUBPROCESS=1` mode) with no coverage collection, no skip-reason
+This is deliberately a **single launcher lane** with no coverage collection, no skip-reason
 allowlist, and no executed-case floor — unlike `vgi-go`'s CI, which covers stdio/launch/shm/http
 lanes and guards against a whole-suite silent skip (a failed `require`/`require-env` is a *skip*,
 not a failure, so "all tests passed" alone isn't proof anything ran). That hardening is a natural

ci/run-integration.sh

@@ -3,9 +3,9 @@
 # example worker, using a prebuilt standalone `haybarn-unittest` and the signed
 # community vgi extension — no C++ build from source. See ci/README.md.
 #
-# Ported from vgi-go's ci/run-integration.sh, trimmed to a single (stdio)
-# transport lane for this first version — vgi-go's version additionally covers
-# launch:/shm/http lanes with a skip-reason allowlist and an executed-case
+# Ported from vgi-go's ci/run-integration.sh, trimmed to a single launcher
+# transport lane — vgi-go's version additionally covers stdio/shm/http lanes
+# with a skip-reason allowlist and an executed-case
 # floor to catch silent whole-suite skips; that hardening is a natural
 # follow-up here once this lane is proven green in real CI (see ci/README.md).
 #
@@ -95,9 +95,15 @@ mkdir -p "$STAGE/test/support"
 install -m 0755 "$DATABASE_WORKER_FIXTURE" \
   "$STAGE/test/support/database_worker_fixture.sh"
 
-# Matches scripts/run_tests.sh's SUBPROCESS=1 lane — the default DuckDB
-# `LOCATION` subprocess transport, no launcher/AF_UNIX pooling.
-export VGI_TEST_WORKER="$WORKER"
+# Pool the main worker behind DuckDB's AF_UNIX launcher. The suite opens many
+# connections and ATTACHes the same worker repeatedly; a bare path starts a new
+# .NET process for each connection, while launch: reuses one warm process.
+export VGI_TEST_WORKER="launch:$WORKER"
+export VGI_REQUIRE_LAUNCHER_TRANSPORT=1
+
+# Keep the small stateful and deliberately-incompatible fixtures isolated.
+# They account for only a handful of tests, and process isolation prevents
+# their mutable/error state from contaminating the shared main worker.
 export VGI_SIMPLE_WRITABLE_WORKER="$SIMPLE_WRITABLE"
 export VGI_BAD_PROTOCOL_WORKER="$BAD_PROTOCOL"