feat(wall-posts): add wall post reading/writing with comments (v1.3.0)

- Add get_wall_posts: read recent wall posts with like/comment counts
- Add create_wall_post: publish new status posts to the wall
- Add add_comment: add comments to wall posts and activities
- like_post already supports both wall posts and activities (v1.2.0)
- Update README.md with new Wall & Activities section
- Update CLAUDE.md with v1.3.0 and tool reorganization
- Update CHANGELOG.md with v1.3.0 release notes
- Add wallpublish and walladdComment documentation to SPEC.md

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

README.md

@@ -2,7 +2,16 @@
 
 MCP server for [Family Wall](https://www.familywall.com) — manage your family's circles, lists, tasks, recipes, and meal plan directly from Claude.
 
-## Tools (v1.0.0)
+## Tools (v1.3.0)
+
+### Wall & Activities
+
+| Tool | Description |
+|---|---|
+| `get_wall_posts` | Get recent wall posts (text, author, likes, comments) |
+| `create_wall_post` 🔒 | Create a new status post on the wall |
+| `add_comment` 🔒 | Add a comment to a post |
+| `like_post` 🔒 | Like or unlike a wall post/activity |
 
 ### Circles & Members