fix(claude): default background text generation to haiku 5.5

[maria-rcks]

Claude background text generation still defaulted to Haiku 4.5 despite Haiku 5.5 being available. Use Haiku 5.5 when selecting a default Claude writer; preserve saved model choices, including legacy 4.5 IDs.

Validation: serverSettings.test.ts (59 tests) passed on Blacksmith. Contracts typecheck and targeted lint passed (existing warnings only). Live provider verification is pending.

Written with gpt-6.1-sol through the Codex harness.

[macroscopeapp]

Approvability

Verdict: Not approved

Macroscope's review found this PR not approvable — This PR changes the product default Claude model used for fallback/background text generation, affecting users without an explicit model selection. Although the implementation is small and covered by a test, product-default changes require human review.

Notes:

• All code in this push has already been reviewed. Approvability was decided on eligibility alone.

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[coderabbitai]

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ℹ️ Recent review info

⚙️ Run configuration

• Configuration used: Path: .coderabbit.config.ts
• Review profile: CHILL
• Plan: Advanced
• Run ID: 741c94c6-91b4-4103-aee1-38ca6412e1cb

📥 Commits

Reviewing files that changed from the base of the PR and between e007f19 and f018f73.

📒 Files selected for processing: 1

• apps/server/src/serverSettings.test.ts

💤 Files with no reviewable changes: 1

• apps/server/src/serverSettings.test.ts

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📝 Walkthrough

The default Claude text-generation model changes to claude-haiku-5-5. The server settings fallback test checks that the fallback selects this model.

Changes: Claude model default

Layer / File(s)	Summary
Update default and verify fallback packages/contracts/src/model.ts, apps/server/src/serverSettings.test.ts	The Claude text-generation default changes to claude-haiku-5-5. The fallback test checks the selected model.

Priority: ⬇️ Low

Estimated code review effort: 1 (Trivial) | ~5 minutes

Change: Bug fix

Merge Risk: ⚪ Minimal · up to f018f

The new Claude default works with the tested fallback path without replacing saved model choices. No issue identified here blocks merging.

Security Architecture Review

Security architecture risk: 🔵 Low · up to e007f

The change retains existing access controls and explicitly saved choices. Compatibility with installed runtime versions remains unverified.

Retained concerns
No architecture-level concerns identified.

Security review details

Security Blast Radius

• inferred — In the traced fallback path, the change affects the model used by an already enabled Claude instance, rather than adding a provider identity or widening eligible instances. The resolver still returns null when no eligible instance is enabled.

Trust Boundaries and Controls

• observed — The existing request constructor keeps the configured command environment and fixed permission flags. Ordinary metadata requests have no executable tools; investigation requests use the existing tool allow/deny lists. Tool authority is selected by the investigation flag, not by the changed default model value. These controls predate this PR.

Pre-merge checks: 4

Passed checks: 4 passed

Check name	Status	Explanation
Linked Issues check		Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check		Check skipped because no linked issues were found for this pull request.
Title check		The title clearly and concisely describes the main change: using Haiku 5.5 as the default Claude model for background text generation.
Description check		The description explains the problem, the change, and focused verification results. It also states that live provider verification is pending and identifies the agent and harness used. It does not inc…

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