feat(functions): add claude-docs and claude-pr helper functions

Add two Claude Code helper functions to streamline common dev workflows:
- `claude-docs`: triggers Claude to sync README.md with recent session changes
- `claude-pr`: triggers Claude to create a branch, commit, push, and open a PR

Also add `.claude` to .gitignore and document both functions in README.md.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.gitignore

@@ -35,3 +35,4 @@ OLD/
 
 # Auto-managed by fish; contains machine-local state and universal vars
 fish_variables
+.claude