feat(loops): injectable completion transport on the worker seam — offline without a mock server

[drewstone]

What

Adds an optional completion transport to the worker seam so benchmarks/agentic runs go fully offline with zero credentials and no localhost server.

RouterConfig gains an optional complete?: (body) => Promise<unknown>. When set, routerChatWithUsage and routerChatWithTools call it with the OpenAI request body and parse the /chat/completions JSON it returns, instead of fetch-ing the router. When absent, the existing fetch path runs unchanged — the live router stays the default, so this is additive with no breaking change.

It is threaded through AgenticOptions → the worker's routerToolLoop cfg, and the analyst's ChatClient is bound to the same injected transport (via agent-eval's mock transport). One injected responder therefore serves both legs of an offline run — the worker's tool-calling turns and the refine/doubleCheck analyst's chat-only steer — exactly as a localhost mock endpoint used to.

Why

examples/strategy-suite previously needed a ~106-line in-process localhost HTTP server (mock-router.ts) just to run offline. The real boundary the worker needs is a single chat-completions call — so make THAT injectable, the same grain ToolLoopChat and agent-eval's ChatClient already use, and the server disappears.

Changes

• src/runtime/router-client.ts — RouterConfig.complete; routerChatWithUsage / routerChatWithTools short-circuit fetch when it is set.
• src/runtime/strategy.ts — AgenticOptions.complete, threaded into the worker loop; new internal analystChat() binds the critic to the same transport when injected.
• src/runtime/router-client.complete.test.ts — locks the contract (uses complete, never fetch; absent ⇒ fetch unchanged).
• examples/strategy-suite/ — rewired to inject a deterministic complete fn; deletes mock-router.ts (106 LOC server); README updated. Live router (TANGLE_API_KEY) stays the drop-in upgrade.

Verify (local)

• pnpm run typecheck (src + examples), pnpm run build, pnpm run lint, pnpm run docs:check — all green.
• pnpm test — 116 files, 1123 passed, 2 skipped, 0 failed (incl. 3 new seam tests).
• Ran strategy-suite offline (no TANGLE_API_KEY) with no mock-router.ts: prints the full leaderboard (sample / refine / doubleCheck all 100% resolved).
• grep confirms 0 references to the deleted mock-router remain.
• Merges cleanly into origin/main (git merge-tree exit 0).

[tangletools]

✅ Auto-approved PR — e3ee0b7f

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_{tangletools · auto-approval · reason: blanket_auto_approve · 2026-06-24T18:09:56Z}