Complete monorepo toolchain setup (tasks 1.1-1.7)

- Turborepo + pnpm workspaces with catalog for shared dependency versions
- TypeScript strict config (base + per-package extends)
- Tailwind CSS v4 via @tailwindcss/vite plugin
- ESLint + Prettier shared config
- Planner app scaffolded with React Router 7 (port 3001)
- Journal app scaffolded with React Router 7 (port 3000)
- Both apps build and start successfully via turbo

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

tsconfig.base.json

@@ -0,0 +1,20 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "module": "ESNext",
+    "moduleResolution": "bundler",
+    "lib": ["ES2022", "DOM", "DOM.Iterable"],
+    "jsx": "react-jsx",
+    "strict": true,
+    "esModuleInterop": true,
+    "skipLibCheck": true,
+    "forceConsistentCasingInFileNames": true,
+    "resolveJsonModule": true,
+    "isolatedModules": true,
+    "declaration": true,
+    "declarationMap": true,
+    "sourceMap": true,
+    "noUncheckedIndexedAccess": true
+  },
+  "exclude": ["node_modules", "build", "dist"]
+}