[Bug] Unexpected model downgrade on simple temperature sensor task

**Bug Description**
this is a simple temperate sensor task on known articles, nothing really special, why have I been swithced down?

**Environment Info**
- Platform: win32
- Terminal: null
- Version: 2.1.268
- Feedback ID: 95f030f0-1510-4129-9094-a81537c4b54a

**Errors**
```json
[{"error":"TelemetrySafeError: VirtualMessageList: itemKeys/messages length desync (keys=191 messages=190 range=[163,191))\n at s4t (B:/~BUN/root/chunk-45p7jdjv.js:36:28828)\n at XSe (B:/~BUN/root/chunk-45p7jdjv.js:36:21633)\n at Br (B:/~BUN/root/chunk-4sm1dhmy.js:18:20036)\n at Hu (B:/~BUN/root/chunk-4sm1dhmy.js:18:38202)\n at qh (B:/~BUN/root/chunk-4sm1dhmy.js:18:84283)\n at _b (B:/~BUN/root/chunk-4sm1dhmy.js:18:83283)\n at ec (B:/~BUN/root/chunk-4sm1dhmy.js:18:83112)\n at Kh (B:/~BUN/root/chunk-4sm1dhmy.js:18:79637)\n at we (B:/~BUN/root/chunk-4sm1dhmy.js:18:6261)\n at nt (B:/~BUN/root/chunk-4sm1dhmy.js:18:4792)","timestamp":"2026-09-11T13:29:48.653Z"}]
```

Start from the Feedback ID and the TelemetrySafeError stack mentioning VirtualMessageList itemKeys/messages length desync in bundled chunk files. Try to reproduce the reported simple temperature sensor task on win32 with version 2.1.268, then trace where model selection and VirtualMessageList state diverge. Done means the downgrade/desync cause is identified and covered by a reproducible fix or test.

索引モデルが issue の本文から書いたものです。