feat: expand scheduling, notifications, and queue runtime

- add scheduled task plumbing across backend core, CLI, and frontend surfaces

- add frontend notification UI and keep service pages using the repaired shared stylesheet

- refactor code queue runtime and update baidu netdisk/service integration docs

src/components/backend-core/Dockerfile

@@ -1,4 +1,5 @@
 FROM oven/bun:1-alpine
+RUN apk add --no-cache postgresql16-client tar gzip
 WORKDIR /app/src/components/backend-core
 COPY src/components/backend-core/package.json ./package.json
 RUN bun install --production