* refactor(session): make ModelLane the provider boundary (#979)
## Summary
This closes the model-lane ownership gap left by #832: `ChatSession` no longer stores raw provider/client handles. `ResolvedModelBinding` now carries the provider, client, model, capabilities, registry generation, and backend-auth configuration as one coherent snapshot.
- Atomically rebind existing sessions after model-registry changes while pinning each in-flight send, fallback, judge, output guard, task agent, title, compaction, perception, and voice operation to its initiating principal and binding.
- Fence UI publication, canonical trajectory folds, durable writes, streams, retries, child scopes, and judge work by generation. Stop can hand off to a successor without accepting late state; cancelled tools retain typed effect receipts, and concurrent approval batches resolve by exact cycle or call.
- Make create, fork, open, close, and delete race-safe with hidden `creating` reservations, incarnation-aware state tails, and an ACL-rechecked transaction that clones checkpoint-bounded history, configuration, project/persona state, and attachment references.
- Extend REST/OpenAPI and Python/TypeScript SDK contracts for create/fork inputs, routed-create metadata, live-workstream probes, targeted approvals, and structured cancellation results.
- Update architecture, storage, authentication, judge, channel, console, API, and SDK documentation, including regenerated architecture diagrams and OpenAPI artifacts.
## Validation
- SQLite suite: 11,188 passed, 9 skipped, 10 deselected
- PostgreSQL suite: 11,195 passed, 2 skipped, 10 deselected
- Live backend: 3 passed
- SSE recovery: 6 passed; browser recovery harness passed all scenarios
- Ruff: clean; 595 files correctly formatted
- mypy: 243 source files clean
- TypeScript: typecheck/build and 35 tests passed
- OpenAPI artifacts fresh; all 14 changed diagrams reproduce byte-for-byte
- `git diff --check` and Git LFS integrity clean
Closes#979.
* fix(deps): update nanoid for GHSA-2v37-7h3g-55p8
Refresh the transitive lock entry admitted by PostCSS so the TypeScript security gate no longer resolves the vulnerable custom-generator implementation.
Validation:
- npm ci
- npm audit --audit-level=moderate: 0 vulnerabilities
- TypeScript typecheck and build
- TypeScript tests: 35 passed
* fix(test): assert canonical model registry URLs
Replace prefix checks with exact canonical base URL assertions so the tests do not model incomplete URL validation.
Validation: tests/test_model_registry.py (185 passed); Ruff check/format; mypy.
turnstone-eval --nudges runs seeded coordinator states against
stimulus arms and scores state-first: cells seed a real task envelope
through the production tasks_add path into a per-run temp DB, the
model's tasks calls really execute, and ground truth is the final
envelope plus a forbidden-action list — robust to action-path
variation, and never tool_choice-forced. Arms render through the
production formatters so the wire carries exactly what production
sends; a body-override lane exists for tuning A/B only and skips the
ablation arm, whose reading only means anything against the body that
ships.
Children are seeded with transcripts — an assignment message, plus a
completion-with-findings for idle children — so honest inspection
finds a world rather than an empty room, and a collect-vs-redo cell
measures the real question. Cell authoring is validated up front
(including refusing a parked task seeded beside an open one, a state
production never sends a body for); mutating calls are scored by what
landed, not by what was attempted.
Instrument health is measured, not assumed: a canary probes tool-call
parsing before and after the sweep, a mid-sweep tripwire aborts a
sweep whose parser dies rather than printing a red grid, and
empty-log runs are labelled harness: so they can never score against
the model.
The coordinator idle-observer test file lands in this commit rather
than the feature commit: its parity guard imports the eval scenarios
to pin the production formatters and the eval wire to one rendering.
Patrick Buckley