Refactor project structure and enhance TypeScript support

- Updated package.json to point to compiled TypeScript files in the dist directory.
- Improved TypeScript configuration with stricter type checks and removed JavaScript support.
- Migrated frontend entry point to TypeScript and added a new App component with enhanced functionality.
- Implemented a new server structure with TypeScript, including WebSocket support and improved element management.
- Updated README to reflect changes in architecture and usage instructions.
- Added comprehensive type definitions for Excalidraw elements and server responses.

tsconfig.json

@@ -3,14 +3,24 @@
     "target": "ES2022",
     "module": "ESNext",
     "moduleResolution": "node",
-    "allowJs": true,
+    "allowJs": false,
     "checkJs": false,
     "declaration": true,
     "declarationMap": true,
     "sourceMap": true,
     "outDir": "./dist",
     "rootDir": "./src",
-    "strict": false,
+    "strict": true,
+    "noImplicitAny": true,
+    "strictNullChecks": true,
+    "strictFunctionTypes": true,
+    "strictBindCallApply": true,
+    "strictPropertyInitialization": true,
+    "noImplicitThis": true,
+    "noImplicitReturns": false,
+    "noFallthroughCasesInSwitch": true,
+    "noUncheckedIndexedAccess": true,
+    "noImplicitOverride": true,
     "esModuleInterop": true,
     "allowSyntheticDefaultImports": true,
     "forceConsistentCasingInFileNames": true,
@@ -23,14 +33,16 @@
     "types": ["node"]
   },
   "include": [
-    "src/**/*"
+    "src/**/*.ts"
   ],
   "exclude": [
     "node_modules",
     "dist",
     "frontend",
-    "**/*.test.js",
-    "**/*.spec.js"
+    "**/*.test.ts",
+    "**/*.spec.ts",
+    "**/*.js",
+    "**/*.jsx"
   ],
   "ts-node": {
     "esm": true