fix(docker): use pnpm --filter for all monorepo package builds

Use pnpm --filter consistently for all three package builds in the
Dockerfile instead of mixing filter and cd approaches. Also set
--project . explicitly on tsc invocations to ensure tsconfig resolution
from the package directory rather than workspace root.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

Dockerfile

@@ -16,7 +16,7 @@ COPY packages/ packages/
 COPY src/ src/
 RUN pnpm --filter @groombook/types build && \
     pnpm --filter @groombook/db build && \
-    /app/node_modules/.bin/tsc -p /app/tsconfig.json
+    pnpm --filter @groombook/api build
 
 # Runtime
 FROM node:20-alpine AS runner