Prepare core alias release notes

docs/roadmap/implementation.md

@@ -728,6 +728,14 @@ deferred-work record and accepted ADR were left unchanged.
 footer are correct. No release launcher, remote push, or tag operation occurs
 as part of implementing this plan.
 
+**Completed:** Added `docs/releases/v0.3.0.md` with the `...Declaration`
+migration, command-slice conversion, function-value signature impact,
+positional `Invocation` guidance, alias behavior, and `-c=` empty-value
+correction. The note retains Go 1.26.0 and maintainer Go 1.26.8 and includes
+candidate-tag links plus the required immutable licensing footer. No published
+release note, dependency version, sum file, tag, or remote was changed. Prepare
+integration dependency adoption only after core v0.3.0 is published.
+
 ## Stage 17: Verify the complete target and finish
 
 **Work**