Tighten engine lifecycle tests that accept any engine error

Description

Found by loop52 review rvc1 (pre-existing): several internal/agento11yprovision lifecycle tests accept any error from the engine without asserting which, e.g. TestEngineCleanupConsumerBarrierTLS/teardown-action passed in a gate run with the last engine return 39 ms after the caller deadline (margin probe left=-39ms). Such a test can pass on a deadline instead of the behaviour it names. Also: the :1561 diagnostic prints originalError/originalCtxErr in apply mode because that branch never assigns them (lifecycle_test.go:1578-1582).

Acceptance Criteria

• #1 Each lifecycle test that expects an engine error asserts the specific error class it is about, and fails on a caller DeadlineExceeded
• #2 The :1561 diagnostic reports apply-mode errors correctly
• #3 No deadline, barrier or production behaviour changes

Definition of Done

• #1 just check (fmt-check, lint, gen-check, env-check, docs-check, test, race, hygiene, ui-check, compose-check, helm-test, lab-check, signal-fidelity)
• #2 just gen (only if a blueprint field, construct/workload config struct, or a skill under plugins/synthkit/skills/ changed)
• #3 just dump — inventory diffed against signals/

Implementation Notes

loop52 BATCH15: landed 8ddc55e. 14 tests require the specific error class; :1621 apply-mode diagnostic fixed; mutation proof 70 subtests; rvc13 PASS; CodeRabbit 0. First gate red only on load-induced lossless-sample deadline (the tightening refusing a deadline base accepted); re-gate on 19a18a3 gaterun 20261022T151607Z-synthkit-8d5b97f7 exit 0. Residual: bare-ErrConflict sites -> SKT-0153.03.04.04.