⚡ Bolt: Cache BlogApp API fetch to prevent redundant requests

[schmug]

💡 What: Added a module-level cache (fetchPromise and cachedPayload) to BlogApp.tsx.
🎯 Why: In the window manager interface, frequently opening and closing the Blog app causes the component to mount/unmount, wiping out local state and triggering redundant /api/blog.json API requests on every open.
📊 Impact: Reduces network traffic and enables instant loads for subsequent opens of the app.
🔬 Measurement: Verify by opening the Blog app, closing it, and opening it again; the second time should load instantly without a network request.

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PR created automatically by Jules for task 11223090085682761477 started by @schmug

[google-labs-jules]

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[schmug]

Superseded by #127 (merged to main), which consolidated the best of the duplicate Bolt/Sentinel/Palette scheduled-agent PRs into one reviewed change. Closing as duplicate.

[google-labs-jules]

Superseded by #127 (merged to main), which consolidated the best of the duplicate Bolt/Sentinel/Palette scheduled-agent PRs into one reviewed change. Closing as duplicate.

Understood. Acknowledging that this work is now superseded by #127 and stopping work on this task.