chore(claude): improve Claude Code integration

- Add Claude Code section to CLAUDE.md pointing to /precommit
- Update .claude/settings.json: move model to user-level,
  normalize uv run permission, remove redundant gh entries
- Add .claude/commands/precommit.md with full pre-commit checklist
- Replace github.copilot-chat with anthropic.claude-code
  in extensions.json

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: nanotaboada

.claude/commands/precommit.md

@@ -0,0 +1,9 @@
+Run the pre-commit checklist for this project:
+
+1. Remind me to update `CHANGELOG.md` `[Unreleased]` section (Added / Changed / Fixed / Removed) — I must do this manually.
+2. Run `uv run flake8 .` — must pass.
+3. Run `uv run black --check .` — must pass (run `uv run black .` to auto-fix).
+4. Run `uv run pytest` — all tests must pass.
+5. Run `uv run pytest --cov=./ --cov-report=term` — coverage must be ≥80%.
+
+Run steps 2–5, report the results clearly, then propose a branch name and commit message for my approval using the format `type(scope): description (#issue)` (max 80 chars; types: `feat` `fix` `chore` `docs` `test` `refactor` `ci` `perf`). Do not create the branch or commit until I explicitly confirm.

.claude/settings.json

@@ -1,10 +1,7 @@
 {
-  "model": "claude-sonnet-4-6",
   "permissions": {
     "allow": [
-      "Bash(gh issue:*)",
-      "Bash(gh auth:*)",
-      "Bash(uv run:*)",
+      "Bash(uv run *)",
       "Bash(source .venv/bin/activate)",
       "WebFetch(domain:github.com)",
       "WebFetch(domain:api.github.com)"

.vscode/extensions.json

@@ -4,7 +4,7 @@
     "ms-python.python",                  // Python language support
 
     // AI Assistance
-    "github.copilot-chat",               // GitHub Copilot Chat - AI-powered coding assistant
+    "anthropic.claude-code",             // Claude Code - AI-powered coding assistant
     "coderabbit.coderabbit-vscode",      // CodeRabbit - AI-powered code review
 
     // Code Quality

CLAUDE.md

@@ -1,3 +1,7 @@
 # CLAUDE.md
 
 @.github/copilot-instructions.md
+
+## Claude Code
+
+- Run `/precommit` to execute the full pre-commit checklist for this project.