test: harden AX content-group path + dedup perform_action probe (1.0.0b13)

[mauricecarrier7]

Fast-follow to #169 (merged as 1b149a5, 1.0.0b12). Addresses the three non-blocking nits raised by #169's architect + QA reviews — nothing else. No behavior change: test hardening + a perform_action probe dedup.

Reviewer findings addressed

1. QA (concern): _frame had zero test coverage. It's monkeypatched away in every content-group test, so neither its CGRect-struct path nor its documented fallback ran. Added direct unit tests against a stubbed ApplicationServices: CGRect-struct → {x,y,width,height}, the (x,y,w,h) tuple fallback, and the None paths (attribute-read failure, value-unwrap failure, malformed rect). ax.py:99 / tests/test_ax_module.py.

2. QA (warning): stop-at-AXGroup up-walk semantics not pinned. The probe fixture's container had no parent, so dropping AXGroup from the stop-set survived (mutation gap). Gave the container a window parent so the up-walk must stop at the nearest AXGroup; if AXGroup is dropped the walk over-climbs to the window and the test fails. Verified: temporarily removed AXGroup from the stop-set → test_position_probe_hits_window_centre failed → restored. ax.py:376 / tests/test_ax_module.py.

3. Architect (perf/warning): redundant _resolve_content_group on the perform_action not-found path. It was resolved twice (carrier search + WKWebView hint), each re-firing a position-probe + full DFS. Now resolved once and reused. Purely removes the duplicate probe — same return values. ax.py:514.

Behavior unchanged

Probe dedup is observably identical: the existing hint tests still pass — test_perform_action_adds_wkwebview_hint_when_zero_actions and test_perform_action_no_hint_when_other_actions_exist, plus test_perform_action_finds_carrier_via_content_group_probe.

Tests

cd simdrive && PYTHONPATH=src python3 -m pytest -q --ignore=tests/test_e2e_testkit.py → 1704 passed, 4 skipped (the e2e suite needs a booted sim and is ignored per convention).

Version

1.0.0b12 → 1.0.0b13 + CHANGELOG entry (Changed: probe dedup, no behavior change + test hardening).

⚠️ ax.py critical-path — architect+QA forge review required before merge; no behavior change (test hardening + probe dedup).

🤖 Generated with Claude Code

[mauricecarrier7]

Closing — superseded by a history-rewrite sanitization pass on main. The fast-follow (_frame test + perform_action probe dedup) will be re-applied on the rewritten main.