Fix: Copy shared/ inside project dir for Turbopack + add symlinks for dev

Turbopack only resolves tsconfig paths within the project root.
Changed @shared/* from ../shared/* to ./shared/* in all tsconfigs.
Docker copies shared/ into the project dir at build time.
Local dev uses symlinks (gitignored).

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

website/.gitignore

@@ -0,0 +1,2 @@
+# Symlink to shared/ (Docker COPY handles this in container)
+shared

website/Dockerfile

@@ -9,9 +9,9 @@ COPY website/package.json website/package-lock.json* ./
 # Install dependencies
 RUN npm install
 
-# Copy source code + shared types
+# Copy source code + shared types (inside project for Turbopack)
 COPY website/ .
-COPY shared/ ../shared/
+COPY shared/ ./shared/
 
 # Build arguments for environment variables
 ARG NEXT_PUBLIC_BILLING_API_URL