Fix API build: shared package emits dist, fix type errors

- packages/shared: tsconfig adds outDir/declaration, package.json adds build script
- apps/api/tsconfig.json: paths now point to shared/dist (.d.ts) instead of source,
  resolves TS6059 rootDir conflict
- apps/api/src/routes/{health,notifications,users}.ts: explicit Router type annotation
  to fix TS2742 portable type inference
- apps/api/src/events/handler.ts: cast via 'as unknown as' to satisfy TS2352
- apps/api/Dockerfile: build shared package before api

apps/api/Dockerfile

@@ -16,6 +16,9 @@ RUN pnpm install --frozen-lockfile
 COPY packages/shared ./packages/shared
 COPY apps/api ./apps/api
 
+# Compila primero el paquete shared (api lo consume vía dist/)
+RUN pnpm --filter @naturcalabacera/shared build
+
 # Compila TypeScript del api
 RUN pnpm --filter @naturcalabacera/api build