feat: add Claude hooks for pre-commit quality gates

[dotNomad]

Summary

• Adds two Claude hooks (.claude/settings.json) to automate quality checks that were previously manual:
  • PostToolUse hook: Runs prettier --write on every file after Edit or Write operations
  • PreToolUse hook: Gates git commit commands by inspecting staged files and conditionally running esbuild, eslint, vitest, and webview build checks
• Adds .claude/hooks/pre-commit-checks.sh implementing the commit gate logic with dependency guards and staged-file detection
• Removes the manual "Pre-Commit Checks" section from CLAUDE.md since hooks now enforce this automatically

Test plan

Locally tested the different flows:

• verified commands that were not git commit passed through immediately with no extra prompting
• verified git commit skipped checks if it was Go code only
• verified that the filtering on the changed files worked
  • extensions/vscode/src/ triggers esbuild, lint, and unit tests
  • Vue files in webviews triggers webview build and lint
• if node_modules weren't installed which is common when using a worktree the message is clear and actionable for Claude to continue
• prettier gets run on all file edits using --ignore-unknown to avoid files Prettier doesn't support just like we do in the package.json npm script

[christierney]

good stuff!