feat: Add VS Code Language Model API integration and Biome linting

.biomeignore

@@ -1,18 +1,18 @@
-# Build output
-out/
-dist/
-
-# Dependencies
-node_modules/
-
-# Type definitions
-**/*.d.ts
-
-# Config files
-webpack.config.js
-
-# VSCode settings
-.vscode/
-
-# Large files
-src/encoder.json
+# Build output
+out/
+dist/
+
+# Dependencies
+node_modules/
+
+# Type definitions
+**/*.d.ts
+
+# Config files
+webpack.config.js
+
+# VSCode settings
+.vscode/
+
+# Large files
+src/encoder.json

.github/RELEASE.md

@@ -0,0 +1,299 @@
+# Release Process Documentation
+
+## Overview
+
+This project uses an automated GitHub Actions workflow for releasing the VS Code extension. The workflow handles version bumping, building, testing, publishing to the marketplace, and creating GitHub releases.
+
+## Prerequisites
+
+### Required Secrets
+
+You need to configure the following secret in your GitHub repository:
+
+1. **`VSCE_PAT`** - Personal Access Token for VS Code Marketplace
+   - Go to [Azure DevOps](https://dev.azure.com/)
+   - Create a new organization or use existing one
+   - Navigate to User Settings → Personal Access Tokens
+   - Create a new token with the following:
+     - **Name**: VS Code Marketplace Publishing
+     - **Organization**: All accessible organizations
+     - **Expiration**: Custom (1 year recommended)
+     - **Scopes**:
+       - Marketplace → **Manage** (required)
+   - Copy the token and add it to GitHub:
+     - Repository Settings → Secrets and variables → Actions
+     - New repository secret: `VSCE_PAT`
+
+## Automated Release Workflow
+
+### Trigger
+
+The release workflow is triggered manually via GitHub Actions:
+
+1. Go to **Actions** tab in your repository
+2. Select **Release Extension** workflow
+3. Click **Run workflow**
+4. Choose version bump type:
+   - **auto** (default): Automatically determines version bump based on commits
+   - **major**: Breaking changes (1.0.0 → 2.0.0)
+   - **minor**: New features (1.1.0 → 1.2.0)
+   - **patch**: Bug fixes (1.1.0 → 1.1.1)
+
+### What the Workflow Does
+
+#### ✅ 1. Version Detection & Validation
+
+- Reads current version from `package.json`
+- Checks if version tag already exists in Git
+- Prevents duplicate releases
+
+#### ✅ 2. Commit Analysis (Auto mode)
+
+- Analyzes commits since last release
+- Determines version bump based on conventional commits:
+  - `feat!:` or `BREAKING CHANGE:` → **major**
+  - `feat:` → **minor**
+  - `fix:`, `chore:`, `docs:` → **patch**
+
+#### ✅ 3. Version Bumping
+
+- Automatically bumps version if tag exists
+- Updates `package.json` and `package-lock.json`
+- Commits changes with message: `chore: bump version to X.Y.Z`
+- Pushes version bump commit
+
+#### ✅ 4. Build & Test
+
+- Runs TypeScript type checking (`npm run type-check`)
+- Runs linter (`npm run lint:check`)
+- Compiles extension (`npm run compile`)
+- Runs test suite (`npm run test`)
+
+#### ✅ 5. Package Extension
+
+- Packages extension as `.vsix` file
+- Names file: `diffy-explain-ai-X.Y.Z.vsix`
+
+#### ✅ 6. Publish to Marketplace
+
+- Publishes extension to VS Code Marketplace
+- Uses `VSCE_PAT` secret for authentication
+- Updates existing extension listing
+
+#### ✅ 7. Create Git Tag
+
+- Creates annotated Git tag: `vX.Y.Z`
+- Pushes tag to repository
+
+#### ✅ 8. Generate Release Notes
+
+- Automatically categorizes commits:
+  - ✨ **Features**: `feat:` commits
+  - 🐛 **Bug Fixes**: `fix:` commits
+  - 📝 **Documentation**: `docs:` commits
+  - 🔧 **Maintenance**: `chore:`, `build:`, `ci:` commits
+- Includes commit hashes for traceability
+
+#### ✅ 9. Create GitHub Release
+
+- Creates GitHub Release with tag
+- Includes auto-generated release notes
+- Attaches `.vsix` file as release asset
+- Not marked as draft or prerelease
+
+#### ✅ 10. Upload Artifacts
+
+- Uploads `.vsix` file as workflow artifact
+- Retention: 90 days
+- Available for download from workflow run
+
+## Version Bump Examples
+
+### Automatic Version Bumping
+
+**Scenario 1**: Bug fixes and chores
+
+```bash
+git log v1.0.0..HEAD
+# - fix: resolve OpenAI API timeout
+# - chore: update dependencies
+# - docs: improve README
+
+Result: 1.0.0 → 1.0.1 (patch)
+```
+
+**Scenario 2**: New features
+
+```bash
+git log v1.1.0..HEAD
+# - feat: add custom commit templates
+# - fix: handle empty diffs
+
+Result: 1.1.0 → 1.2.0 (minor)
+```
+
+**Scenario 3**: Breaking changes
+
+```bash
+git log v2.0.0..HEAD
+# - feat!: redesign AI service interface
+# - BREAKING CHANGE: remove deprecated methods
+
+Result: 2.0.0 → 3.0.0 (major)
+```
+
+### Manual Version Bumping
+
+You can override automatic detection:
+
+1. **Patch Release**: Bug fixes only
+   - Select `patch` in workflow input
+   - 1.1.0 → 1.1.1
+
+2. **Minor Release**: New features
+   - Select `minor` in workflow input
+   - 1.1.0 → 1.2.0
+
+3. **Major Release**: Breaking changes
+   - Select `major` in workflow input
+   - 1.1.0 → 2.0.0
+
+## Manual Release Process
+
+If you need to release manually:
+
+### 1. Update Version
+
+```bash
+npm version patch  # or minor, major
+```
+
+### 2. Build Extension
+
+```bash
+npm run type-check
+npm run lint
+npm run compile
+```
+
+### 3. Package Extension
+
+```bash
+npm install -g @vscode/vsce
+vsce package
+```
+
+### 4. Publish to Marketplace
+
+```bash
+vsce publish -p YOUR_PERSONAL_ACCESS_TOKEN
+```
+
+### 5. Create GitHub Release
+
+```bash
+git tag -a v1.1.0 -m "Release v1.1.0"
+git push origin v1.1.0
+
+# Then create release on GitHub with VSIX file
+```
+
+## Troubleshooting
+
+### Error: "Tag already exists"
+
+The workflow checks if a tag exists and automatically bumps the version. If you see this error:
+
+1. Check existing tags: `git tag -l`
+2. Delete tag if needed: `git tag -d vX.Y.Z && git push origin :refs/tags/vX.Y.Z`
+3. Re-run workflow
+
+### Error: "VSCE_PAT is not set"
+
+1. Verify secret exists in repository settings
+2. Ensure it's named exactly `VSCE_PAT`
+3. Generate new token if expired
+
+### Error: "Extension validation failed"
+
+1. Check `package.json` for required fields
+2. Ensure `engines.vscode` matches `@types/vscode`
+3. Verify all files referenced in `package.json` exist
+
+### Tests Failed
+
+Tests failures won't block the release (marked as `continue-on-error`), but you should:
+
+1. Review test failures in workflow logs
+2. Fix failing tests
+3. Consider making tests blocking by removing `continue-on-error: true`
+
+## Best Practices
+
+### Commit Messages
+
+Use conventional commits for automatic version bumping:
+
+```bash
+# Features (minor bump)
+git commit -m "feat: add new AI model support"
+git commit -m "feat(git): implement file filtering"
+
+# Bug fixes (patch bump)
+git commit -m "fix: resolve memory leak in diff parser"
+git commit -m "fix(ai): handle API rate limiting"
+
+# Breaking changes (major bump)
+git commit -m "feat!: redesign configuration API"
+git commit -m "feat: new config format
+
+BREAKING CHANGE: Configuration schema has changed"
+
+# Other types (patch bump)
+git commit -m "docs: update installation guide"
+git commit -m "chore: update dependencies"
+git commit -m "style: format code with Biome"
+```
+
+### Release Cadence
+
+- **Patch releases**: Weekly or as needed for bug fixes
+- **Minor releases**: Monthly for new features
+- **Major releases**: Quarterly or when breaking changes necessary
+
+### Pre-Release Checklist
+
+Before triggering a release:
+
+1. ✅ Ensure all tests pass locally
+2. ✅ Update CHANGELOG.md if maintained
+3. ✅ Review open issues and PRs
+4. ✅ Test extension locally with `vsce package`
+5. ✅ Verify documentation is up to date
+
+## Monitoring
+
+### After Release
+
+Check the following:
+
+1. **Marketplace**: Extension appears at <https://marketplace.visualstudio.com/items?itemName=hitclaw.diffy-explain-ai>
+2. **GitHub Release**: Release created with VSIX file attached
+3. **Git Tag**: Tag pushed to repository
+4. **Workflow Artifacts**: VSIX available for 90 days
+
+### Rollback
+
+If you need to rollback a release:
+
+1. Unpublish from marketplace (contact VS Code team)
+2. Delete GitHub release
+3. Delete Git tag: `git push origin :refs/tags/vX.Y.Z`
+4. Revert version in `package.json`
+
+## Resources
+
+- [Publishing Extensions](https://code.visualstudio.com/api/working-with-extensions/publishing-extension)
+- [Conventional Commits](https://www.conventionalcommits.org/)
+- [Semantic Versioning](https://semver.org/)
+- [GitHub Actions Documentation](https://docs.github.com/en/actions)

.github/workflows/main.yml

@@ -1,28 +1,31 @@
-name: Node.js CI
-
-on:
-  push:
-    branches: ["main"]
-  pull_request:
-    branches: ["main"]
-
-jobs:
-  build:
-    runs-on: ubuntu-latest
-
-    strategy:
-      matrix:
-        node-version: [16.x, 18.x]
-        # See supported Node.js release schedule at https://nodejs.org/en/about/releases/
-
-    steps:
-      - uses: actions/checkout@v3
-      - name: Use Node.js ${{ matrix.node-version }}
-        uses: actions/setup-node@v3
-        with:
-          node-version: ${{ matrix.node-version }}
-          cache: "npm"
-      - run: npm install
-      - run: npm run type-check
-      - run: npm run lint
-      - run: npm run compile
+name: Node.js CI
+
+on:
+  push:
+    branches: ["main"]
+  pull_request:
+    branches: ["main"]
+
+permissions:
+  contents: read
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        node-version: [16.x, 18.x]
+        # See supported Node.js release schedule at https://nodejs.org/en/about/releases/
+
+    steps:
+      - uses: actions/checkout@v3
+      - name: Use Node.js ${{ matrix.node-version }}
+        uses: actions/setup-node@v3
+        with:
+          node-version: ${{ matrix.node-version }}
+          cache: "npm"
+      - run: npm install
+      - run: npm run type-check
+      - run: npm run lint
+      - run: npm run compile