ci(ios): a regular depth-1 snapshot carries XCTest tree quality metadata when the AX bridge probe circuit is open #3328

Purpose

File the currently untracked iOS Smoke failure signature "regular depth-1 snapshot must not carry XCTest tree quality metadata" so #2491's lane report covers every signature that fails on main, and decide which side owns it: the acquisition fallback or the assertion.

Evidence (both on main)

• Run 37145696803 (2026-10-03, d396f3b50), job Smoke Tests
• Run 37459193672 (2026-10-06, 1163b7ac0), job Smoke Tests

Failing assertion, test/integration/ios-simulator-e2e/live-snapshot-depth-frontier.ts:126 (assertSimulatorBridgeSnapshot, reached from assertRegularVisibleDepthFrontier on the step capture regular visible-depth frontier):

AssertionError [ERR_ASSERTION]: regular depth-1 snapshot must not carry XCTest tree quality metadata
+ actual   'tree'
- expected undefined

The response it asserts on keeps the fallback disclosure on a regular (non-raw) snapshot:

"snapshotQuality": { "state": "healthy", "backend": "tree", "timing": { "acquisitionMs": 64.7, "presentationMs": 0.09 } },
"warnings": ["Simulator AX snapshot unavailable (circuit-disabled); used XCTest for this app generation."],
"snapshotDiagnostics": { "stats": { "backends": { "xctest": 53 }, "maxMs": 27409 } }

The same two runs' runner log shows the acquisition path that produced it:

AGENT_DEVICE_RUNNER_PRIVATE_AX_SNAPSHOT_DEPTH_RETRY depth=64 error=Could not match active AX application for XCTest application
... depth=56, depth=40, depth=24, depth=12 ...
AGENT_DEVICE_RUNNER_PRIVATE_AX_SNAPSHOT_FAILED=Could not match active AX application for XCTest application
AGENT_DEVICE_RUNNER_SNAPSHOT_BACKEND_FAILED backend=tree error=the XCTest tree capture exceeded its 8s time slice

So the bridge was circuit-disabled for that app generation, the capture fell back to the XCTest tree, and a regular snapshot carried the tree backend's quality metadata that the lane asserts must be absent.

Required behavior

• State the contract explicitly: may a regular (non-raw) snapshot ever carry XCTest snapshotQuality/backend disclosure on the simulator? Today the runner and the assertion disagree.
• If a bridge-disabled fallback is legitimate for a regular snapshot, the assertion must assert the disclosed fallback through a typed acquisition reason instead of demanding absence. If it is not legitimate, the fallback must not be reachable for a regular snapshot, and the owning seam is snapshot acquisition classification (refactor(apple-runner): classify AX snapshot failure once at acquisition #2972), not a call-site guard.
• Key the decision on typed acquisition reasons and snapshotQuality state, never on the warning string.
• Decide whether the combination "probe circuit open for the app generation" plus "XCTest tree capture exceeded its time slice" is a product defect or a lane condition ci(ios): the iOS simulator smoke lane is failing on main across several rotating signatures #2491 should classify explicitly.

Completion

• One live iOS Simulator run reaches the circuit-disabled state and the resulting regular snapshot --depth 1 either carries no tree quality metadata or the smoke assertion asserts the disclosed fallback, whichever the decision is.
• ci(ios): the iOS simulator smoke lane is failing on main across several rotating signatures #2491 lists this signature as tracked rather than unfiled.

Related

#2972 (classify AX snapshot failure once at acquisition), #2492 (bridge probe circuit follow-ups), #2491 (the lane report this belongs to).