[kbaker827]

Refs #69

Summary

From the traceback on #69:

• Clearing the proxy GATT cache is best effort, but a slow proxy raised a bare TimeoutError and aborted the update. It is now logged and the update continues.
• BLETimeoutError is not a BLEConnectionError, so it escaped the handler that already tolerates a failed app-mode connect and flashes through the AppLoader. It now takes that path.
• A BLETimeoutError during the flash now reports as a failed update, not an unexpected error.

The OTA deadline still fires: asyncio.timeout raises CancelledError inside the await, so the new inner except TimeoutError cannot swallow it.

Test plan

• Three new tests, failed before the change
• Full suite passes. Run locally on Windows with small local stand-ins for the Unix and BlueZ modules Home Assistant needs (not part of this PR), so CI on Linux is the first clean run.
• Not run on Solum/Silabs hardware. These are the failures in the traceback, so please confirm a real update before closing Firmware update of silabs fails on 3.0 beta 7 #69

🤖 Generated with Claude Code

[kbaker827]

CI is waiting on maintainer approval here, so I ran the workflows on my fork at 3825d19:

• Tests: passed, on both the latest and min-ha Home Assistant, plus ruff
• hassfest: passed
• HACS: 8 of 10 checks passed. The two failures are fork settings (issues disabled, no topics), and the fork's unmodified main fails the same two.

This covers this branch on its own, not merged with the other open PRs, and nothing has been run on real hardware.