Derive module release identity and accept full Git tags

docs/roadmap/implementation.md

@@ -177,6 +177,12 @@ or malformed declarations, and selection outside the repository. Test committed
 versus working-tree readers and full slash-containing Git refs. Update synthetic
 fixtures that need genuine module declarations. Run affected package tests.
 
+**Completed:** Added shared committed and working-tree module identity derivation,
+module-local note paths, and literal Git tag-reference validation. Verified root,
+nested, physical-major, and ordinary `v2` layouts, committed versus working-tree
+declarations, and slash-containing local and remote tag operations. `go test ./...`
+passes.
+
 ## Stage 2: Carry identity through facade types and candidate capture
 
 **Outcome:** Candidate capture supplies module-local notes and recoverable identity