Initial scaffold: pnpm workspace monorepo with backend + frontend

- Backend: Express + WebSocket proxy (tsx watch, strict TS, ESM)
- Frontend: React 19 + Vite + Monaco + Tailwind v4 + Tauri v2
- pnpm workspace at root for single-install workflow
- AGENTS.md with architectural constraints and commands
- Removed Tauri greet demo, added minimal App shell
- No external database, Git-as-Database philosophy

README.md

@@ -0,0 +1,58 @@
+# typst-leaf 🍂
+
+A completely self-hostable, high-performance editor for [Typst](https://typst.app/), built on the philosophy of "Git as the Database."
+
+**Features:**
+* **Instant Preview:** Sub-50ms incremental compilation using `tinymist`.
+* **Vim Mode:** First-class support via Monaco.
+* **Git Native:** No hidden databases. Your projects are just folders with `.git`.
+* **Hybrid:** Run it in Docker on your server, or as a native desktop app via Tauri.
+
+## 📂 Repository Structure
+
+```text
+typst-leaf/
+├── typst-leaf-backend/     # Node.js/TS server (manages tinymist & git)
+├── typst-leaf-frontend/    # React + Monaco frontend (includes Tauri)
+├── VISION.md               # Project philosophy and architecture
+└── AGENTS.md               # Guidelines for AI coding assistants
+
+```
+
+## 🚀 Quick Start (Development)
+
+**Prerequisites:**
+
+* Node.js 20+
+* pnpm
+* Rust (for Tauri)
+* `tinymist` binary installed in your PATH.
+
+```bash
+# 1. Install dependencies
+pnpm install
+
+# 2. Start the backend (Port 4000)
+cd typst-leaf-backend
+pnpm dev
+
+# 3. Start the web frontend (Port 3000)
+# (In a new terminal)
+cd typst-leaf-frontend
+pnpm dev
+
+# 4. Start Tauri Desktop App (Optional)
+# (In a new terminal)
+cd typst-leaf-frontend
+pnpm tauri dev
+
+```
+
+## 🏗️ Architecture
+
+* **Editor:** Monaco Editor
+* **LSP:** `tinymist` (via WebSocket proxy)
+* **Communication:**
+    * `ws://localhost:4000/lsp` -> Tinymist Language Server
+    * `ws://localhost:4000/preview` -> Tinymist Preview Service
+