[financial-services] [BUG] Claude for M365 (Bedrock direct): 400 "thinking.adaptive.block_binding: Extra inputs are not permitted" with Opus 4.6

## Observed symptom [BUG] Claude for M365 (Bedrock direct): 400 "thinking.adaptive.block_binding: Extra inputs are not permitted" with Opus 4.6 Environment - Path: Bedrock direct (entra_sso=1), manifest generated with build-manifest.mjs - Add-in version: [ip], build 5f2d8b3776a49427ae7f9cf4688aa08c58be3576 - Host: Excel on Windows (Microsoft 365) - aws_region: eu-central-1 Steps 1. Sign in with Entra ID (works, role is assumed) 2. Select Opus 4.6 in the model picker 3. Send any message ## Environment GitHub anthropics/financial-services #379 ## Trigger / context Public GitHub report in anthropics/financial-services (FRESH_7D). ## Source evidence - https://github.com/anthropics/financial-services/issues/379 (2026-09-30T15:07:28Z) — evidence_class: PRIMARY_ISSUE_REPORT — #379 ## Freshness - classification: FRESH_7D - retrieved_at: 2026-10-02T10:50:53.329738Z - scout_id: C5fbb5c6c0b ## Scout notes This Problem was published by the KFA Fresh Friction Scout from public sources. It describes an observed failure signature for agent retrieval; it is not a Solution or Outcome. Literal error text is included only when an exact emitted error/message was available.