fix: share one model resolver between the daemon and the web client

[saucam]

Symptom

/model opus is rejected in the web UI as an unknown model, while the daemon behind it resolves the same input fine.

Cause

Model-value resolution existed twice:

Copy	Where
resolveAgainstList	src/daemon/models.ts
resolveModelInput	web/src/state/models.ts — a hand-maintained mirror

They drifted. #315 taught the daemon copy to match a bare alias against a variant-suffixed value — the backend reports {"value": "opus[1m]", "displayName": "Opus (1M context)"}, so a typed opus matches neither field verbatim. The mirror kept the old rule, so the client returned null and reported an unknown model before the request was ever sent.

Change

Patching the mirror would leave two copies and the same drift. The resolver moves into @highflame/codeoid-core, which already exists for daemon/frontend shared logic — the re-export shims in web/src/lib/{approvals,identity,format}.ts are the established pattern.

packages/core/src/models.ts   ← the one implementation
src/daemon/models.ts          ← re-exports it (37 lines of duplicate deleted)
web/src/state/models.ts       ← resolveModelInput delegates to it

Daemon behaviour is unchanged; the client now matches it. The web client keeps its own pre-catalog passthrough — with an empty list the trimmed input goes through untouched so typing isn't blocked before the fetch lands, and the daemon remains the backstop validator either way.

Verification

• packages/core + daemon model tests — 52 pass
• web suite — 434 pass across 41 files
• bun run typecheck (root + protocol + core) and cd web && tsc --noEmit — clean
• bun run lint — clean

Coverage moves to packages/core alongside the code, using the live supportedModels() payload from claude-agent-sdk 0.3.258 as the fixture, plus a web-side regression test that drives the real symptom end-to-end through fetchModels → resolveModelInput.

Notes for the reviewer

• The picker already renders opt.value beneath the display name (SessionControls.tsx, unchanged since July), so Fable 5 vs 5.1 is already distinguishable there — the backend's display name is just "Fable" for both. No UI change was needed and none is included.
• Unrelated, noticed while working: web/dist is served at /ui and is built separately, so a daemon restart does not pick up frontend changes — this fix needs bun run build:web to reach a browser.

🤖 Generated with Claude Code

[highflame-oracle]

🔮 Oracle Review

🎯 Start Here

packages/core/src/index.ts (~15 min) — Logic changes in index.ts

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📋 PR Summary

What this PR does: fix: share one model resolver between the daemon and the web client

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🔍 Code Review

Review completed.

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