fix: copy src/ directory into Docker image for notification module

The notification routes import from src/encryptid/db which was missing
from the production container, causing a crash loop on startup.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Dockerfile

@@ -39,6 +39,7 @@ COPY --from=build /app/server ./server
 COPY --from=build /app/lib ./lib
 COPY --from=build /app/shared ./shared
 COPY --from=build /app/modules ./modules
+COPY --from=build /app/src ./src
 COPY --from=build /app/package.json .
 COPY --from=build /encryptid-sdk /encryptid-sdk