fix(wall-posts): add delete_wall_post and fix add_comment response parser (v1.3.1)

- Fix add_comment response parser: corrected to a00.r.r.comment.commentId structure
- Fix add_comment error handling: return errors directly instead of warnings
- Add delete_wall_post: permanently delete wall posts via metadelete endpoint
- Add delete_wall_post to README.md Wall & Activities section
- Update SPEC.md with correct walladdComment response structure
- Update SPEC.md metadelete to include wall posts as supported type
- Update CHANGELOG.md with v1.3.1 bugfixes and additions
- Version bumped to 1.3.1 in pyproject.toml

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

CHANGELOG.md

@@ -10,6 +10,21 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 This project follows Semantic Versioning (SemVer).
 Breaking changes (removed tools, changed parameters) increment the major version.
 
+## [1.3.1] – 2026-04-17
+
+### Fixed
+- **`add_comment` response parser**: corrected response structure from `a00.r.r` with `metaId`
+  to nested `a00.r.r.comment.commentId`; response now includes `"created": true` flag
+- **`add_comment` error handling**: now returns error messages directly instead of warnings
+
+### Added
+- **`delete_wall_post`** — permanently delete a wall post using the `metadelete` endpoint
+  (identical to deleting tasks and recipes)
+
+### Notes
+- All wall post tools now complete CRUD operations (Create, Read, Update via like_post, Delete)
+- Test post (wall/16282169_31146617) removed from production after verification
+
 ## [1.3.0] – 2026-04-17
 
 ### Added