Add fixture for CC v2.1.126 auto-mode red-stalled spinner

[itsdestin]

Surfaced by /release v1.2.2 → next review (review-cc-changes agent).

CC v2.1.126 CHANGELOG:

Auto mode: the spinner now turns red when a permission check stalls, instead of looking like the tool is running.

YouCoded's attention classifier matches ` …` from `getScreenText` (xterm's plain-text buffer, ANSI stripped). Color is ANSI-driven, so the glyph itself should still match — the classifier shouldn't break — but the v1.2.3 release window also touched `attention-classifier.ts` and `useAttentionClassifier.ts` (commit 669fc86), so we should verify the new red-stalled-permission case is covered before assuming.

What to do

1. Add a new fixture pair under `shared-fixtures/attention-classifier/` capturing the auto-mode red-stalled spinner scenario — either by:
   • Running `node test-conpty/test-attention-states.mjs` against CC 2.1.126 with `--permission-mode auto` and a tool call that hits a permission boundary, or
   • Hand-crafting a `.input.json` with the expected ANSI-stripped buffer text and a `.expected.json` describing the intended state.
2. Confirm `classifyBuffer` returns the right state — most likely `'thinking-stalled'` (since CC is signaling stall), not `'thinking-active'` or `'ok'`.
3. Run the parity test (`desktop/tests/attention-classifier.test.ts`) and confirm the new fixture passes.

Related

• `youcoded/docs/cc-dependencies.md` "PTY spinner regex (attention-classifier)" — the touchpoint that motivated the agent flagging this.
• `shared-fixtures/attention-classifier/` — the fixture directory.