Add shared resource naming primitives

docs/roadmap/implementation.md

@@ -334,6 +334,11 @@ Scope: small private domain helpers and focused behavior tests.
 Validation: `GOWORK=off go test ./internal/domain`. Test selected naming behavior,
 not a helper call sequence or invented character restrictions.
 
+Completion: private resource-ID, namespace, local-key, qualification, and
+namespace-extraction helpers are implemented with focused grammar and spelling
+tests. Validation passed: `GOWORK=off go test ./internal/domain` and
+`git diff --check`.
+
 ## Stage 3: Make Configuration Processing Path-Aware
 
 Scope: preparation refactor inside `internal/configuration`; current format stays.