Monorepo Integration: Unified Backend, Frontend & Documentation

- Reorganize project into monorepo structure
  - backend/app/ - New FastAPI backend (modular with src/)
  - backend/legacy/ - Legacy database modules (relational & vector)
  - frontend/ - React text editor application

- Add launcher.py for easy full-stack startup
- Complete documentation in README.md
  - Quick start guide
  - API endpoints reference
  - Development setup
  - Troubleshooting

- Refactor main.py to 35 lines (app configuration only)
- Update .gitignore for full-stack project
- Add CHANGELOG.md with version history (v0.1.0-v0.1.1)

Structure is now clean and ready for team collaboration.

frontend/package.json

@@ -0,0 +1,40 @@
+{
+  "name": "text-editor",
+  "version": "0.0.1",
+  "private": true,
+  "dependencies": {
+    "@tiptap/extension-character-count": "^3.20.1",
+    "@tiptap/extension-image": "^3.20.1",
+    "@tiptap/extension-link": "^3.20.1",
+    "@tiptap/extension-mathematics": "^3.20.1",
+    "@tiptap/extension-table": "^3.20.1",
+    "@tiptap/extension-table-cell": "^3.20.1",
+    "@tiptap/extension-table-header": "^3.20.1",
+    "@tiptap/extension-table-row": "^3.20.1",
+    "@tiptap/extension-underline": "^3.20.1",
+    "@tiptap/react": "^3.20.1",
+    "@tiptap/starter-kit": "^3.20.1",
+    "katex": "^0.16.38",
+    "mathlive": "^0.109.0",
+    "react": "^18.2.0",
+    "react-dom": "^18.2.0",
+    "react-scripts": "5.0.1",
+    "web-vitals": "^5.1.0"
+  },
+  "scripts": {
+    "start": "react-scripts start",
+    "build": "react-scripts build"
+  },
+  "browserslist": {
+    "production": [
+      ">0.2%",
+      "not dead",
+      "not op_mini all"
+    ],
+    "development": [
+      "last 1 chrome version",
+      "last 1 firefox version",
+      "last 1 safari version"
+    ]
+  }
+}