feat(check): retire the thinking-disabled workaround — effort buys extended thinking

[RobbieMcKinstry]

The cersei pin predated the provider's ability to round-trip Anthropic
thinking blocks: its SSE parser dropped signature_delta, so the thinking
block echoed back on the second turn carried an empty signature and the API
rejected it. Effort was therefore applied as a sampling temperature, with a
comment promising to revisit once fixed upstream.

wack/cersei (now the authoritative source; we are not tracking pacifio
upstream) carries the fixes: 94f18b2 accumulates the signature from
signature_delta and 5bd06db preserves redacted_thinking across turns.
Bump the pin (d485d50 -> 4dfac7f — which also brings the bounded,
gitignore-aware GlobTool that closes the unbounded-walk timeout vector)
and map effort onto its natural vehicle:

• medium/high enable extended thinking (4096/8192-token budgets, cersei's
  own EffortLevel scale, safely under the 16k default max_tokens);
• low — the default — keeps thinking off for speed and cost, steering with
  temperature exactly as before (0.0, +0.5 per retry attempt).

Exactly one control is applied per run: the API rejects a temperature when
thinking is enabled (thinking samples at 1.0, which also gives thinking
retries the trajectory diversity that attempt_temperature provides on
thinking-free runs).

Not yet verified against the live API (no credentials in the build
environment): a multi check --effort medium run on a real project should
confirm turn-2 thinking blocks are accepted before this merges.

Co-Authored-By: Claude Fable 5 noreply@anthropic.com
Claude-Session: https://claude.ai/code/session_01VxKv1hhPZ4GocfmwHUk1G8

[RobbieMcKinstry]

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• feat(check): retire the thinking-disabled workaround — effort buys extended thinking #153 👈 (View in Graphite)
• fix(check): stop check agents from getting lost outside their sandbox #152
• fix(check): stop multi check from hanging on exit after a run completes #151
• feat(check): opt-in session-trace archive for multi check #150
• fix(check): stop the presenter and CLAUDE.md loading from corrupting output #149
• trunk

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