chore: add GitHub CI, release workflow, and contributor docs

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,27 @@
+---
+name: Bug report
+about: Report a problem with Tab Group Sync
+labels: bug
+---
+
+## Describe the bug
+A clear and concise description of what the bug is.
+
+## To reproduce
+1. ...
+2. ...
+3. ...
+
+## Expected behavior
+What you expected to happen.
+
+## Actual behavior
+What actually happened.
+
+## Environment
+- Chrome version:
+- Extension version:
+- OS:
+
+## Screenshots / logs
+If applicable, attach screenshots or relevant console logs.

.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,17 @@
+---
+name: Feature request
+about: Suggest an enhancement
+labels: enhancement
+---
+
+## Problem
+What problem are you trying to solve? What is the use case?
+
+## Proposed solution
+How would you like it to work?
+
+## Alternatives considered
+Other approaches you thought about.
+
+## Additional context
+Any other context, mockups, or examples.

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,19 @@
+## Summary
+<!-- What does this PR do, and why? -->
+
+## Related spec / issue
+<!-- Link to .kiro/specs/<name>/ or GitHub issue -->
+
+## Changes
+-
+-
+
+## Test plan
+- [ ] `npm test` passes
+- [ ] `npm run test:e2e` passes (if UI or background changes)
+- [ ] Manually loaded `dist/` in Chrome and verified affected flows
+
+## Checklist
+- [ ] Spec updated (`requirements.md` / `design.md` / `tasks.md`) if scope changed
+- [ ] `progress.txt` reflects task completion
+- [ ] No personal data, secrets, or credentials added

.github/workflows/ci.yml

@@ -0,0 +1,26 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: '20'
+          cache: 'npm'
+
+      - run: npm ci
+
+      - name: Typecheck and build
+        run: npm run build
+
+      - name: Unit and property tests
+        run: npm test

.github/workflows/release.yml

@@ -0,0 +1,47 @@
+name: Release
+
+on:
+  push:
+    tags:
+      - 'v*.*.*'
+
+permissions:
+  contents: write
+
+jobs:
+  release:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: '20'
+          cache: 'npm'
+
+      - run: npm ci
+
+      - name: Build extension
+        run: npm run build
+
+      - name: Verify tag matches manifest version
+        run: |
+          TAG_VERSION="${GITHUB_REF_NAME#v}"
+          MANIFEST_VERSION=$(node -p "require('./manifest.json').version")
+          if [ "$TAG_VERSION" != "$MANIFEST_VERSION" ]; then
+            echo "Tag version ($TAG_VERSION) does not match manifest.json version ($MANIFEST_VERSION)"
+            exit 1
+          fi
+
+      - name: Package dist as zip
+        run: |
+          cd dist
+          zip -r "../tab-group-sync-${GITHUB_REF_NAME}.zip" .
+
+      - name: Create GitHub Release
+        uses: softprops/action-gh-release@v2
+        with:
+          files: tab-group-sync-*.zip
+          generate_release_notes: true
+          draft: false
+          prerelease: false

CHANGELOG.md

@@ -0,0 +1,27 @@
+# Changelog
+
+All notable changes to this project are documented here. The format follows
+[Keep a Changelog](https://keepachangelog.com/en/1.1.0/) and this project
+adheres to [Semantic Versioning](https://semver.org/).
+
+## [Unreleased]
+
+## [1.2.0]
+
+### Added
+- Move tab groups across windows with human-friendly window labels
+  (group names → active tab title/domain → generic fallback)
+- Welcome page shown on first install
+- Bundled privacy policy page
+- Expanded in-app help dialog
+
+### Changed
+- Service worker reliability improvements and move-aware sync guards
+- Bounded history retention (ring buffer + age pruning)
+
+## [1.1.0]
+
+### Added
+- Initial public feature set: automatic tab group backup to bookmarks,
+  cross-device sync via Chrome bookmark sync, snapshots, selective sync,
+  auto-sync, auto-cleanup, export/import.

CONTRIBUTING.md

@@ -0,0 +1,50 @@
+# Contributing
+
+Thanks for your interest in Tab Group Sync. This project follows a spec-driven development workflow.
+
+## Workflow
+
+1. **Find or file an issue** describing the problem or feature.
+2. **Check the spec** under `.kiro/specs/<spec-name>/`:
+   - `requirements.md` — system of record for what the feature does
+   - `design.md` — architecture, properties, pseudocode
+   - `tasks.md` — implementation tasks and status
+   - `progress.txt` — audit log of task completion
+3. **Implement** against the spec. If scope changes, update the spec first.
+4. **Test** — unit, property, and E2E tests are expected for non-trivial changes.
+5. **Open a PR** using the template.
+
+## Development
+
+```bash
+npm install
+npm run build          # build extension into dist/
+npm run watch          # rebuild on change
+npm test               # unit + property tests
+npm run test:e2e       # E2E tests (builds first)
+```
+
+Load the unpacked extension from `dist/` via `chrome://extensions` → Developer mode.
+
+## Testing expectations
+
+- **Unit tests** (Vitest) for pure logic and edge cases
+- **Property tests** (fast-check) for invariants — see `tests/property/PROPERTY_COVERAGE.md`
+- **E2E tests** (Playwright) interact through the popup UI only — no internal API access
+
+## Release process
+
+Releases are driven by git tags:
+
+1. Bump `version` in `manifest.json` and `package.json` (must match).
+2. Update `CHANGELOG.md`.
+3. Merge to `main`.
+4. Tag: `git tag v1.2.0 && git push origin v1.2.0`
+5. The `release` workflow builds, packages `dist/` as a zip, and attaches it to a GitHub Release.
+6. Upload the same zip to the Chrome Web Store.
+
+The release workflow verifies the tag version matches `manifest.json` and fails if they drift.
+
+## Code conventions
+
+See `.kiro/steering/` for product, tech, and structure guidelines.

README.md

@@ -1,7 +1,14 @@
 # Tab Group Sync
 
+[![CI](https://github.com/kundeng/tabgroupsync/actions/workflows/ci.yml/badge.svg)](https://github.com/kundeng/tabgroupsync/actions/workflows/ci.yml)
+
 A Chrome extension that automatically synchronizes tab groups with bookmark folders, enabling users to save and restore tab group layouts across devices and browser sessions.
 
+## Install
+
+- **Releases**: download the latest `tab-group-sync-v*.zip` from [GitHub Releases](https://github.com/kundeng/tabgroupsync/releases), unzip, then load in Chrome via `chrome://extensions` → Developer mode → Load unpacked.
+- **Chrome Web Store**: _coming soon_
+
 ## Features
 
 *(sourced from [requirements.md](.kiro/specs/tab-group-sync/requirements.md))*
@@ -60,6 +67,10 @@ See [Property Coverage](tests/property/PROPERTY_COVERAGE.md) and [E2E README](te
 | [docs/TECHNICAL.md](docs/TECHNICAL.md) | Learning guide and technical reference |
 | [KNOWN_ISSUES.md](docs/KNOWN_ISSUES.md) | Known limitations and edge cases |
 
+## Contributing
+
+See [CONTRIBUTING.md](CONTRIBUTING.md) for the spec-driven workflow and release process.
+
 ## License
 
 MIT License