A procedural universe, and an observatory that has to find what is in it

README.md

@@ -191,8 +191,10 @@ in [`CONTRIBUTING.md`](./CONTRIBUTING.md).
 
 > [!CAUTION]
 > **This line will not load worlds created by the 2.x Advanced Rocketry fork.** The save format changed with
-> no migration path. Procedural-universe parameters are the same story: they are inputs to a derived
-> universe, so changing one relocates every star and every coordinate a player wrote down. Start a new world.
+> no migration path. Procedural-universe parameters are a milder story: they are inputs to a derived
+> universe, so changing one moves every system nobody has visited yet — the world therefore refuses to
+> open under a changed configuration, and `/stellurgy universe upgrade` is the deliberate way through,
+> freezing everything already explored. See the planetDefs reference before you touch them.
 
 ## For pack developers
 
@@ -203,6 +205,7 @@ Stars, planets, planet types, the procedural galaxy and ores are configured in X
 templates in [`docs/`](docs/):
 
 - planetDefs — [reference](docs/README_PLANETDEFS.md) · [template](docs/TEMPLATE_planetdefs.xml)
+  — every element and attribute, its unit, and what wins when two of them disagree
 - oreConfig — [reference](docs/README_ORECONFIG.md) · [template](docs/TEMPLATE_oreconfig.xml)
 
 Coming from an older 2.x build: commands moved into subcommands, so **command scripts and quest-book command

build.gradle

@@ -315,6 +315,14 @@ def configureHeadlessTest = { Test t, String packageGlob ->
     })
     // Test-only flag gating /artest probe commands and other test-only behaviour.
     t.systemProperty 'advancedrocketry.tests', 'true'
+    // Forward the golden-corpus rewrite flag into the forked test JVM. Regenerating the universe
+    // fixture is a deliberate act (it means a new schema version is being released), so it is opt-in
+    // per invocation rather than a property with a default:
+    //   ./gradlew testUnit --rerun -Dadvancedrocketry.universe.corpus.write=true
+    if (System.getProperty('advancedrocketry.universe.corpus.write') != null) {
+        t.systemProperty 'advancedrocketry.universe.corpus.write',
+                System.getProperty('advancedrocketry.universe.corpus.write')
+    }
     t.testLogging {
         events 'failed', 'skipped', 'passed'
         exceptionFormat = 'full'