Change-detectors, tautologies, source-reading tests, redundant duplicates,
mock-echo tests and dead/unrunnable tests. Per-test rationale in the lane
ledger (category + reason for every removal).
_resolve_from_pool now calls pool.select(model=...) so the per-model
Anthropic cooldown can be honoured at resolve time. Two untouched sibling
test files stubbed the pool with `select=lambda: entry`, which rejects the
keyword and turned CI red (4 failures: TypeError unexpected keyword
argument 'model'). Widen both stubs to `lambda **_kw: entry`, the same
shape test_credential_pool_provider_boundary.py already uses.
Also carry the per-model 429 paragraph and the sibling-module bullet into
the zh-Hans credential-pools mirror, which the review flagged as stale.
