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

packages/shared/package.json

@@ -0,0 +1,13 @@
+{
+  "name": "@tessera/shared",
+  "version": "0.0.1",
+  "private": true,
+  "main": "src/index.ts",
+  "types": "src/index.ts",
+  "scripts": {
+    "type-check": "tsc --noEmit"
+  },
+  "devDependencies": {
+    "typescript": "^5.5.0"
+  }
+}

packages/shared/src/index.ts

@@ -0,0 +1,6 @@
+export const APP_NAME = "Tessera";
+
+export interface HealthResponse {
+  status: string;
+  timestamp: string;
+}

packages/shared/tsconfig.json

@@ -0,0 +1,8 @@
+{
+  "extends": "../../tsconfig.base.json",
+  "compilerOptions": {
+    "outDir": "./dist",
+    "rootDir": "./src"
+  },
+  "include": ["src"]
+}