fix(evidence): bind corpus to workspace identity

.superpowers/sdd/evidence-task-5c-report.md

@@ -122,3 +122,16 @@ and the final full harness plus scoped Ruff/diff invocation completed with exit
 Final focused verification: `89 passed` across corpus/CLI JSON, direct/HTTP parity, migrations, and
 real Docker pgvector lifecycle; scoped Ruff and `git diff --check` clean. A contemporaneous full-suite
 run reached unrelated Task 6 immutable-file tamper tests; those files were deliberately not changed.
+
+## Immutable corpus/workspace binding
+
+- A corpus root becomes bound to the workspace id persisted in its ACTIVE manifest. Job, non-job,
+  explicit GC, and ACTIVE search entry points compare the configured namespace before discovery,
+  vector access, staging, deletion, or ACTIVE mutation.
+- Reusing the same paths after renaming a workspace now fails closed with a typed/sanitized message:
+  use a new corpus root or perform an intentional explicit rebuild. Unscoped legacy manifests also
+  fail this ownership check.
+- Tests prove unchanged-document reuse cannot silently mix workspace A vectors into a workspace B
+  manifest, and that mismatched job, GC, and search paths perform no vector/filesystem mutations.
+
+Focused workspace-binding, search-pack, preprocess JSON, and scoped Ruff/diff tests pass.