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