chore(config): pin @types/bun, tighten TypeScript strictness, and refactor config logic

- Pin `@types/bun` to `^1.3.14` for reproducible builds instead of using `latest`
- Update `tsconfig.json` with stricter type-checking flags and reorganize compiler options
- Refactor `initConfig` to DRY up the model default logic and add a null guard before process exit

tsconfig.json

@@ -1,29 +1,39 @@
 {
+  // Visit https://aka.ms/tsconfig to read more about this file
   "compilerOptions": {
-    // Environment setup & latest features
-    "lib": ["ESNext"],
-    "target": "ESNext",
-    "module": "Preserve",
-    "moduleDetection": "force",
-    "jsx": "react-jsx",
-    "allowJs": true,
-
-    // Bundler mode
+    // Environment Settings
+    // See also https://aka.ms/tsconfig/module
+    "module": "esnext",
+    "target": "esnext",
     "moduleResolution": "bundler",
-    "allowImportingTsExtensions": true,
-    "verbatimModuleSyntax": true,
+    "esModuleInterop": true,
     "noEmit": true,
+    // For nodejs:
+    "lib": ["esnext"],
+    "types": ["bun"],
+    // and npm install -D @types/node
 
-    // Best practices
-    "strict": true,
-    "skipLibCheck": true,
-    "noFallthroughCasesInSwitch": true,
+    // Stricter Typechecking Options
     "noUncheckedIndexedAccess": true,
-    "noImplicitOverride": true,
+    "exactOptionalPropertyTypes": true,
 
-    // Some stricter flags (disabled by default)
-    "noUnusedLocals": false,
-    "noUnusedParameters": false,
-    "noPropertyAccessFromIndexSignature": false
+    // Style Options
+    "noImplicitReturns": true,
+    "noImplicitOverride": true,
+    "noUnusedLocals": true,
+    "noUnusedParameters": true,
+    "noFallthroughCasesInSwitch": true,
+    "noPropertyAccessFromIndexSignature": true,
+
+    // Recommended Options
+    "strict": true,
+    "jsx": "react-jsx",
+    //"allowImportingTsExtensions": true,
+    "allowArbitraryExtensions": true,
+    "verbatimModuleSyntax": true,
+    "isolatedModules": true,
+    "noUncheckedSideEffectImports": true,
+    "moduleDetection": "force",
+    "skipLibCheck": true
   }
 }