T5 — contract snapshots

2026-10-13, branch loop/issue-36, Python 3.14, local Temporal dev server (start_local).

`uv run pytest tests/contract`

text

37 passed in 3.60s
exit=0

Snapshots changed on purpose (each regenerated with UPDATE_API_SNAPSHOTS=1 and reviewed in the diff):

Snapshot	Change
`settings.schema.json`	`[agent]` (`id`, `name`, `description`); `temporal.task_queue` optional, default the agent id
`tiny_harness.config.txt`	`AgentConfig`, `DEFAULT_AGENT_ID`, `Settings.agent`, `TemporalConfig.task_queue: str \| None`
`tiny_harness.errors.txt`	`HarnessConflictError`, `HarnessAlreadyStartedError`, `HarnessStoppedError`, `HarnessNotStartedError`
`tiny_harness.service.txt`	`Harness`, `RouteOptions`, `harnesses_lifespan`
`tiny_harness.fastapi.txt` (new)	`harness_router(harness, *, tags=None) -> APIRouter`

agent-card.json is unchanged (R7.3): the default agent at the root builds the same card.