feat(update): 调整更新阻塞逻辑

[HarcoChen]

允许下载时启动任务，改为pending状态才阻塞更新

Summary by Sourcery

Refine update-blocking logic so that only a pending/downloaded update install blocks auto task startup, allowing background downloads to proceed concurrently with task execution.

Bug Fixes:

• Prevent auto-install from triggering while an auto-started task dispatch is still in progress, avoiding premature update installation for small downloads.

Enhancements:

• Only block dispatch of auto-start tasks when an update package is already downloaded and pending install, not while the update is still downloading in the background.
• Add a settlement callback mechanism so task start events can report completion status back to the update logic and trigger a follow-up install check.

[sourcery-ai]

Hey - I've reviewed your changes and they look great!

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[sourcery-ai]

Hey - I've reviewed your changes and they look great!

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_{Help me be more useful! Please click 👍 or 👎 on each comment and I'll use the feedback to improve your reviews.}