feat(01-01): monorepo scaffold with root configs and shared package

- Root package.json with pnpm workspace, Turborepo, Biome, TypeScript
- pnpm-workspace.yaml defining apps/* and packages/* workspaces
- turbo.json with build, dev, lint, type-check task definitions
- tsconfig.base.json with strict mode and bundler module resolution
- biome.json with formatter and linter configuration
- .gitignore, .env.example, .dockerignore
- @tessera/shared package with APP_NAME constant and HealthResponse type
- pnpm-lock.yaml generated from successful install

tsconfig.base.json

@@ -0,0 +1,17 @@
+{
+  "compilerOptions": {
+    "strict": true,
+    "esModuleInterop": true,
+    "skipLibCheck": true,
+    "forceConsistentCasingInFileNames": true,
+    "resolveJsonModule": true,
+    "isolatedModules": true,
+    "moduleResolution": "bundler",
+    "module": "ESNext",
+    "target": "ES2022",
+    "declaration": true,
+    "declarationMap": true,
+    "sourceMap": true,
+    "composite": false
+  }
+}