diff --git a/.gitignore b/.gitignore
index 3c5c9c2..2a5d880 100644
--- a/.gitignore
+++ b/.gitignore
@@ -46,9 +46,10 @@ Thumbs.db
 *.tmp
 *.bak
 
-# Markdown: only README.md is versioned
+# Markdown: only README.md and CHANGELOG.md are versioned
 *.md
 !README.md
+!CHANGELOG.md
 
 # Frontend (React dashboard)
 frontend/node_modules/
diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000..153b437
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,58 @@
+# Changelog
+
+All notable changes to Sentinel are documented here.
+
+## [0.2.0] - 2026-09-01
+
+### Added
+
+#### Frontend Features
+- **Toast notifications** — success/error/info toasts with 4s auto-dismiss (`Toast.tsx`)
+- **Keyboard shortcuts** — `1`/`2` switch tabs, `Escape` dismisses panels (`useKeyboardShortcuts.ts`)
+- **History panel** — last 10 analyses stored in localStorage (`HistoryPanel.tsx`, `useHistory.ts`)
+- **Share button** — copy analysis URL to clipboard (`ShareButton.tsx`)
+- **Export** — download results as JSON or CSV (`ExportButton.tsx`)
+- **Caching** — 5-minute client-side cache for repeated analyses (`api.ts`)
+- **Performance tracking** — shows "Analyzed in X.Xs" (`usePerformance.ts`)
+- **Analytics** — localStorage-based event tracking, max 50 events (`useAnalytics.ts`)
+- **Responsive mobile cards** — improved violation cards with file count, line-clamp, component overflow (`ViolationsTab.tsx`)
+- **Error boundary** — React class component with retry (`ErrorBoundary.tsx`)
+- **Meta tags** — Open Graph + Twitter Card for social sharing (`index.html`)
+
+#### Backend Improvements
+- **Concurrency limiter** — `asyncio.Semaphore(3)` prevents resource exhaustion, returns 429 on limit
+- **Input validation** — Pydantic validators for GitHub URL regex + branch sanitization
+- **Git clone timeout** — 60s timeout on `git clone --depth=1`
+- **FQN resolution** — Java and C# parsers return full FQN (`com.example.model.User` instead of `User`)
+
+#### Infrastructure
+- **CI pipeline** — GitHub Actions: lint (ruff), test matrix (Python 3.12 + 3.13, Ubuntu + Windows), frontend build
+- **Pre-deploy script** — `scripts/deploy_check.py` validates lint, format, tests, build, security
+- **Code splitting** — Manual Vite chunks: vendor (~182KB), motion (~133KB), index (~42KB)
+- **Test isolation** — `afterEach(cleanup)` in test-setup.ts, `clearCache()` in api tests
+
+### Fixed
+- **Desktop expand bug** — nested `<button>` violation (aria-expanded on parent), `sm:hidden` on expanded details
+- **Manifest rule keys** — `VALID_RULE_KEYS` expanded from 2 to 9 identifiers (hyphen style matching actual rules)
+- **Float thresholds** — `rule_threshold()` returns `int | float` instead of truncating to `int`
+- **AnimatePresence jsdom** — removed from mobile expanded content (animations don't resolve in jsdom)
+- **API test pollution** — cache clearing between tests prevents cross-test state leakage
+
+### Removed
+- **LoadingState.tsx** — dead code, replaced by skeleton components
+
+## [0.1.0] - 2026-08-30
+
+### Added
+- Initial release
+- 8 architecture detection rules (layer violation, circular dependency, god module, high coupling, low cohesion, boundary crossing, React component, database leakage)
+- tree-sitter parsers for TypeScript, JavaScript, Python, Java, C#
+- Architecture manifest YAML format
+- Drift score computation
+- Git blame integration for origin commits
+- CLI with 6 commands: analyze, graph, trend, history, report, serve
+- HTML report generator with Chart.js
+- FastAPI stateless backend
+- React dashboard with Tailwind CSS v4
+- Vitest + testing-library frontend tests
+- 126 Python backend tests
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..06e2b11
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 Sentinel Contributors
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/README.md b/README.md
index 0fd508a..8a7eab9 100644
--- a/README.md
+++ b/README.md
@@ -9,7 +9,7 @@ reports violations, and tracks regression across git history.
 
 [![Python 3.12+](https://img.shields.io/badge/python-3.12+-blue.svg)](https://www.python.org/downloads/)
 [![License: MIT](https://img.shields.io/badge/license-MIT-green.svg)](LICENSE)
-[![Tests](https://img.shields.io/badge/tests-138%20passed-brightgreen.svg)]()
+[![Tests](https://img.shields.io/badge/tests-141%20passed-brightgreen.svg)]()
 [![Live Demo](https://img.shields.io/badge/demo-live-ff69b4.svg)](https://sentinel-zxr.pages.dev)
 
 [**Try it live**](https://sentinel-zxr.pages.dev) — no installation required
@@ -33,7 +33,7 @@ Sentinel analyzes your repository's dependency graph and compares it against a d
 | Low cohesion | Module with poor internal cohesion (LCOM heuristic) | warning |
 | Boundary crossing | Non-layer code importing sentinel markers | warning |
 | React component | Non-UI layer importing React components | warning |
-| Drift score | Violations introduced or resolved between commits | info |
+| Database leakage | Direct dependencies to data-layer modules | warning |
 
 Every violation includes the **origin commit** — the last commit that touched the offending file.
 
@@ -91,13 +91,17 @@ Optional tuning:
 rules:
   god_module: { threshold: 12 }    # total coupling (fan-in + fan-out)
   high_coupling: { threshold: 5 }  # fan-in (number of dependents)
+  low_cohesion: { threshold: 0.3 } # cohesion score (0.0-1.0)
+  boundary_crossing: { threshold: 3 }
+  react_component: { max_lines: 150, max_props: 8 }
+  database_leakage: { threshold: 2 }
 ```
 
 **No manifest?** Sentinel still runs 6 of 8 rules (all except layer violation and database leakage).
 
 ## Supported Languages
 
-TypeScript, JavaScript, Python, Java, and C#. Imports are resolved to files by matching module references against project file stems.
+TypeScript, JavaScript, Python, Java, and C#. Imports are resolved to files by matching module references against project file stems. Full FQN resolution for Java (`com.example.model.User`) and C# (`Namespace.Class`).
 
 ## How It Works
 
@@ -122,6 +126,46 @@ Repository
 | Cost | Free (SaaS + CLI) | Free tier limited, paid for teams |
 | Languages | TS, JS, Python, Java, C# | 20+ via plugins |
 
+## Deployment
+
+Sentinel runs as a stateless SaaS:
+
+- **Backend**: FastAPI on SnapDeploy (auto-sleep, Docker)
+- **Frontend**: React on Cloudflare Pages (free tier)
+
+The backend has no database or auth — a single `POST /api/analyze` endpoint clones the repo, runs analysis, and returns results.
+
+## Frontend Features
+
+- **Toast notifications** — success/error/info with auto-dismiss
+- **Keyboard shortcuts** — `1`/`2` switch tabs, `Escape` dismisses
+- **History panel** — last 10 analyses stored in localStorage
+- **Share button** — copy analysis URL to clipboard
+- **Export** — download results as JSON or CSV
+- **Caching** — 5-minute client-side cache for repeated analyses
+- **Performance tracking** — shows analysis duration
+- **Responsive design** — mobile-optimized violation cards
+- **Dark/Light mode** — toggle with localStorage persistence
+- **Error boundary** — graceful recovery from rendering errors
+
+## CI/CD
+
+GitHub Actions runs on every push to `main` and every PR:
+
+| Job | What it runs |
+|-----|-------------|
+| `lint` | `ruff check` + `ruff format --check` on backend |
+| `test` | `pytest` on Python 3.12 + 3.13 (Ubuntu + Windows matrix) |
+| `dashboard` | `npm run test` + `npm run build` on frontend |
+
+Pre-deploy validation:
+
+```bash
+python scripts/deploy_check.py
+```
+
+Runs lint, format, tests, frontend build, and security checks before deployment.
+
 ## Development
 
 ```bash
@@ -145,54 +189,80 @@ Tests use synthetic repos of known architecture (`GOOD`, `BAD`, `EVOLVING`) so e
 
 ```
 sentinel/
-├── src/sentinel/              # Core library
-│   ├── parsers/               # tree-sitter language parsers
-│   ├── analyzers/             # coupling, cohesion analysis
-│   ├── rules/                 # 8 detection rules
-│   ├── domain/                # Manifest, Violation types
-│   ├── manifest/              # YAML loader
-│   ├── persistence/           # SQLite run storage
-│   ├── reports/               # HTML report generator
-│   ├── violation_engine.py
-│   ├── trend.py               # Regression detection
-│   ├── cli.py                 # Typer CLI
-│   └── server.py              # HTTP server
-├── backend/                   # SaaS API (FastAPI, stateless)
-├── frontend/                  # React dashboard
+├── src/sentinel/                  # Core library
+│   ├── parsers/                   # tree-sitter language parsers
+│   │   ├── base.py                # Parser ABC
+│   │   ├── registry.py            # Extension-to-parser mapping
+│   │   ├── typescript.py          # TS/JS parser
+│   │   ├── python_lang.py         # Python parser
+│   │   ├── java.py                # Java parser (full FQN)
+│   │   └── csharp.py              # C# parser (full FQN)
+│   ├── analyzers/                 # coupling, cohesion, drift analysis
+│   ├── rules/                     # 8 detection rules
+│   ├── domain/                    # Manifest, Violation, Graph types
+│   ├── manifest/                  # YAML loader + layer mapper
+│   ├── persistence/               # SQLite run storage
+│   ├── reports/                   # HTML report generator
+│   ├── violation_engine.py        # Orchestrates analysis pipeline
+│   ├── trend.py                   # Regression detection
+│   ├── git_origin.py              # Git blame integration
+│   ├── cli.py                     # Typer CLI (6 commands)
+│   └── server.py                  # stdlib HTTP server
+├── backend/                       # SaaS API (FastAPI, stateless)
+│   ├── main.py                    # FastAPI app + CORS
+│   ├── config.py                  # Pydantic settings
+│   ├── routers/analyses.py        # POST /api/analyze
+│   └── services/analysis.py       # Clone + analyze + cleanup
+├── frontend/                      # React dashboard
 │   ├── src/
-│   │   ├── components/        # UI components
+│   │   ├── components/            # 16 UI components
 │   │   │   ├── AnalyzeForm.tsx
-│   │   │   ├── SummaryCards.tsx
-│   │   │   ├── MetricsBar.tsx
+│   │   │   ├── ErrorBoundary.tsx
+│   │   │   ├── ExportButton.tsx
+│   │   │   ├── HistoryPanel.tsx
+│   │   │   ├── ShareButton.tsx
+│   │   │   ├── Toast.tsx
 │   │   │   ├── ViolationsTab.tsx
-│   │   │   ├── RemediationTab.tsx
-│   │   │   └── LoadingState.tsx
-│   │   ├── __tests__/         # Vitest + testing-library
-│   │   ├── api.ts             # Backend client
-│   │   ├── App.tsx            # Root component
-│   │   └── index.css          # Tailwind v4 theme
+│   │   │   └── ...
+│   │   ├── hooks/                 # 5 custom hooks
+│   │   │   ├── useAnalytics.ts
+│   │   │   ├── useHistory.ts
+│   │   │   ├── useKeyboardShortcuts.ts
+│   │   │   ├── usePerformance.ts
+│   │   │   └── usePrefersReducedMotion.ts
+│   │   ├── __tests__/             # Vitest + testing-library
+│   │   ├── api.ts                 # Backend client + cache
+│   │   └── App.tsx                # Root component
 │   └── package.json
-├── tests/                     # 126 Python tests
-└── sentinel.yaml              # Example manifest
+├── tests/                         # 126 Python tests
+├── scripts/deploy_check.py        # Pre-deploy validation
+├── .github/workflows/ci.yml       # CI pipeline
+├── Dockerfile                     # Multi-stage build
+├── fly.toml                       # Fly.io config
+├── .env.example                   # Environment variables
+└── pyproject.toml                 # Package config
 ```
 
 ### Frontend Stack
 
+- **React 19** — UI framework
+- **TypeScript 6.0** — type safety
+- **Vite 8.2** — build tool with manual chunks
 - **Tailwind CSS v4** — CSS-first config, no `tailwind.config.js`
 - **Geist Sans + Mono** — typography
 - **lucide-react** — icons
-- **framer-motion** — animations (shimmer, blur-fade, number-ticker)
-- **Vitest + testing-library** — 12 frontend tests
-- **Dark/Light mode** — toggle with `localStorage` persistence
+- **framer-motion** — animations
+- **Vitest 4.1 + testing-library** — 15 frontend tests
 
 ## Contributing
 
 1. Fork the repo
 2. Create a feature branch (`git checkout -b feat/my-feature`)
 3. Make changes with tests
-4. Run `ruff check src tests && ruff format src tests && python -m pytest tests/`
-5. Open a PR against `main`
+4. Run backend checks: `ruff check src tests && ruff format src tests && python -m pytest tests/`
+5. Run frontend checks: `cd frontend && npm run test && npm run build`
+6. Open a PR against `main`
 
 ## License
 
-MIT
+[MIT](LICENSE)
diff --git a/frontend/README.md b/frontend/README.md
index d6af7e3..13f0025 100644
--- a/frontend/README.md
+++ b/frontend/README.md
@@ -1,32 +1,90 @@
-# React + TypeScript + Vite
+# Sentinel Frontend
 
-This template provides a minimal setup to get React working in Vite with HMR and some Oxlint rules.
+React dashboard for the Sentinel architecture erosion detector.
 
-Currently, two official plugins are available:
+## Stack
 
-- [@vitejs/plugin-react](https://github.com/vitejs/vite-plugin-react/blob/main/packages/plugin-react) uses [Oxc](https://oxc.rs)
-- [@vitejs/plugin-react-swc](https://github.com/vitejs/vite-plugin-react/blob/main/packages/plugin-react-swc) uses [SWC](https://swc.rs/)
+- **React 19** + **TypeScript 6.0**
+- **Vite 8.2** with manual chunks (vendor, motion, index)
+- **Tailwind CSS v4** (CSS-first, no config file)
+- **Geist Sans + Mono** typography
+- **lucide-react** icons
+- **framer-motion** animations
+- **Vitest 4.1** + **testing-library** for tests
 
-## React Compiler
+## Setup
 
-The React Compiler is not enabled on this template because of its impact on dev & build performances. To add it, see [this documentation](https://react.dev/learn/react-compiler/installation).
+```bash
+npm install
+```
+
+## Environment Variables
+
+| Variable | Default | Description |
+|----------|---------|-------------|
+| `VITE_API_URL` | `""` (same origin) | Backend API URL for `/api/analyze` |
+
+Create `.env` for local development:
 
-## Expanding the Oxlint configuration
+```
+VITE_API_URL=http://localhost:8000
+```
 
-If you are developing a production application, we recommend enabling type-aware lint rules by installing `oxlint-tsgolint` and editing `.oxlintrc.json`:
+## Commands
 
-```json
-{
-  "$schema": "./node_modules/oxlint/configuration_schema.json",
-  "plugins": ["react", "typescript", "oxc"],
-  "options": {
-    "typeAware": true
-  },
-  "rules": {
-    "react/rules-of-hooks": "error",
-    "react/only-export-components": ["warn", { "allowConstantExport": true }]
-  }
-}
+```bash
+npm run dev      # Start dev server (http://localhost:5173)
+npm run build    # Production build to dist/
+npm run test     # Run Vitest tests
+npm run lint     # Run oxlint
 ```
 
-See the [Oxlint rules documentation](https://oxc.rs/docs/guide/usage/linter/rules) for the full list of rules and categories.
+## Project Structure
+
+```
+frontend/src/
+├── components/            # UI components
+│   ├── AnalyzeForm.tsx    # Repo URL + branch input form
+│   ├── ErrorBoundary.tsx  # React error boundary
+│   ├── ExampleRepos.tsx   # Pre-filled example repos
+│   ├── ExportButton.tsx   # Export to JSON/CSV
+│   ├── FeatureCards.tsx   # Landing page feature cards
+│   ├── HistoryPanel.tsx   # Past analysis history
+│   ├── HowItWorks.tsx     # How-it-works explainer
+│   ├── MetricsBar.tsx     # Metrics display bar
+│   ├── RemediationTab.tsx # Remediation suggestions
+│   ├── ShareButton.tsx    # Copy analysis URL
+│   ├── SkeletonCards.tsx  # Loading skeleton
+│   ├── SkeletonMetrics.tsx
+│   ├── SkeletonTable.tsx
+│   ├── SummaryCards.tsx   # Summary stat cards
+│   ├── Toast.tsx          # Toast notification system
+│   └── ViolationsTab.tsx  # Violations table/display
+├── hooks/
+│   ├── useAnalytics.ts          # localStorage event tracking
+│   ├── useHistory.ts            # Analysis history (max 10)
+│   ├── useKeyboardShortcuts.ts  # 1/2 tabs, Escape dismiss
+│   ├── usePerformance.ts        # Analysis time tracking
+│   └── usePrefersReducedMotion.ts
+├── __tests__/             # Vitest + testing-library
+├── api.ts                 # Backend client + 5min cache
+├── App.tsx                # Root component
+└── index.css              # Tailwind v4 theme
+```
+
+## Testing
+
+Tests run in jsdom. React 18+ StrictMode renders twice, so:
+- Use `getAllBy` with `.at(-1)` for queries matching multiple elements
+- Animations (framer-motion) don't resolve in jsdom — avoid `AnimatePresence` in tested paths
+
+```bash
+npm run test
+```
+
+## Build
+
+Production build outputs to `dist/` with manual chunks:
+- `vendor` (~182KB): React, ReactDOM, react-dom
+- `motion` (~133KB): framer-motion
+- `index` (~42KB): app code