Evidence: the refactor changed nothing, and the contract cannot drift (issue-212)

Testing-plan rows T3, T4 and T5.

T4 — the whole suite, before and after the refactor

The tasks file sets a checkpoint after T4: "the refactor is complete and behaviour-neutral: the whole existing suite must pass with no test adapted. If a test needed changing, the refactor was not neutral." It held. The run below is immediately after T1–T4 (routes extracted to api/routes.py, per-request behaviour moved onto the route class, build_lifespan extracted, build_app given an optional allowlist) and before a single line of the_loop/sdk/ existed:

$ uv run --project cli pytest cli/tests -q
2041 passed, 1 skipped in 98.85s (0:01:38)

No test file was touched to get there. That is the whole claim of D1/D2: create_app lost its middleware and its three exception handlers, and the served surface is identical.

T4 — the whole suite, with the SDK

$ uv run --project cli python -m pytest -q cli
2098 passed, 1 skipped in 96.29s (0:01:36)

57 new tests, no regressions, the skip is the pre-existing one.

T3 + T5 — the parity gates

$ uv run --project cli python -m pytest cli/tests/test_sdk_docs_parity.py \
      cli/tests/test_api_contract_parity.py -q
......                                                                   [100%]
6 passed in 1.49s

Four of the six are new or extended:

Assertion	What it stops
test_the_router_carries_exactly_the_apps_operations	a route reaching the standalone app but not the embeddable router (they are the same object; this is what proves it stayed that way)
test_p1_every_public_symbol_is_documented	shipping a public SDK name nobody wrote up
test_p2_every_namespace_method_reaches_core	a rename in core leaving an SDK method that raises at runtime
test_p3 / test_p4	REQUIREMENTS and docs/sdk/environment.md naming different binaries, in either direction

The pre-existing test_served_schema_matches_the_authored_contract still passes unchanged, so the chain is complete: router == served app == authored OpenAPI contract.

Gate: how many operations

mount() reports 29 operations; the host application's OpenAPI document shows 28 paths under the prefix. Both are right — /api/v1/config carries GET and POST on one path.