feat: migrate from Next.js Pages Router to App Router with Payload CMS

Complete architectural overhaul migrating from Directus+tRPC to Payload CMS with Next.js App Router. This represents a fundamental shift in how the application is structured and how data is managed.

Major changes:
- Migrated from Pages Router (src/pages/) to App Router (src/app/)
- Replaced Directus CMS with Payload CMS as the content management system
- Removed tRPC in favor of Payload's built-in API routes
- Added PostgreSQL database via Docker Compose for local development
- Implemented separate route groups for frontend and Payload admin
- Updated all API routes to App Router conventions
- Added Payload collections for Projects, Technologies, Links, Media, and Users
- Configured ESLint for new project structure

Infrastructure:
- Added docker-compose.yml for PostgreSQL database
- Updated environment variables for Payload CMS configuration
- Integrated @payloadcms/next for seamless Next.js integration
- Added GraphQL API and playground routes

Dependencies:
- Upgraded React from 18.2.0 to 19.2.0
- Upgraded Next.js to 15.5.6
- Added Payload CMS 3.x packages (@payloadcms/db-postgres, @payloadcms/next, etc.)
- Removed Directus SDK and tRPC packages
- Updated Sharp to 0.34.x
- Migrated to @tanstack/react-query v5

tsconfig.json

@@ -1,11 +1,10 @@
 {
   "compilerOptions": {
-    "target": "es2017",
-    "lib": ["dom", "dom.iterable", "esnext"],
+    "baseUrl": ".",
+    "lib": ["DOM", "DOM.Iterable", "ES2022"],
     "allowJs": true,
     "skipLibCheck": true,
     "strict": true,
-    "forceConsistentCasingInFileNames": true,
     "noEmit": true,
     "esModuleInterop": true,
     "module": "esnext",
@@ -14,11 +13,17 @@
     "isolatedModules": true,
     "jsx": "preserve",
     "incremental": true,
-    "noUncheckedIndexedAccess": true,
+    "plugins": [
+      {
+        "name": "next"
+      }
+    ],
     "paths": {
-      "@/*": ["./src/*"]
-    }
+      "@/*": ["./src/*"],
+      "@payload-config": ["./src/payload.config.ts"]
+    },
+    "target": "ES2022"
   },
-  "include": ["next-env.d.ts", "**/*.ts", "**/*.tsx", "**/*.cjs", "**/*.mjs"],
+  "include": ["next-env.d.ts", "**/*.ts", "**/*.tsx", ".next/types/**/*.ts"],
   "exclude": ["node_modules"]
 }