docs: update CONTRIBUTING.md with lint and test steps, remove duplicate PR template

.github/PULL_REQUEST_TEMPLATE.md

@@ -1,25 +0,0 @@
-## Description
-
-<!-- What does this PR do? Why is it needed? -->
-
-## Type of Change
-
-- [ ] 🐛 Bug fix
-- [ ] ✨ New feature
-- [ ] 💅 Style / UI change
-- [ ] ♻️ Refactor (no behavior change)
-- [ ] 📝 Documentation
-- [ ] 🧪 Tests
-- [ ] 🔧 Build / CI / tooling
-
-## Checklist
-
-- [ ] `npm run build` passes with zero errors
-- [ ] Tested in browser (dev server or production build)
-- [ ] Commit messages follow [Conventional Commits](https://www.conventionalcommits.org/)
-- [ ] No secrets or credentials included
-- [ ] Translations updated in `src/lib/i18n.ts` if UI text changed
-
-## Screenshots
-
-<!-- If this changes the UI, add before/after screenshots or a short GIF -->

CONTRIBUTING.md

@@ -26,8 +26,10 @@ Thanks for your interest in contributing! 🦞
 
 ## Development
 
-- **Build:** `npm run build` — must pass with 0 errors before submitting a PR
 - **Dev server:** `npm run dev` — starts Vite with hot reload
+- **Lint:** `npm run lint` — must pass with 0 errors and 0 warnings
+- **Test:** `npm test` — runs Vitest unit tests (must all pass)
+- **Build:** `npm run build` — must pass with 0 errors before submitting a PR
 - **Preview:** `npx vite preview` — serve the production build locally
 
 ### Project Structure
@@ -48,7 +50,12 @@ src/
 
 1. Create a feature branch: `git checkout -b feat/my-feature`
 2. Make your changes
-3. Ensure `npm run build` passes with no errors
+3. Ensure all checks pass:
+   ```bash
+   npm run lint    # 0 errors, 0 warnings
+   npm test        # all tests pass
+   npm run build   # 0 errors
+   ```
 4. Commit using [Conventional Commits](https://www.conventionalcommits.org/):
    - `feat:` — new feature
    - `fix:` — bug fix