[abrichr]

Follow-up to #1727, from agnostic-repair's live run on the UTM Windows lab. The app's "Session notice" dialog covers the right part of the identity band but not its center, so the center rule returned None and the repair never applied.

What changed

• Intersects, not covers the center. The topmost window of the app's own process whose owner chain reaches the captured window, and which meets the region, is now reported. The "covers the region's center" rule is gone.
• Unchanged: any other process's window, or an app window not owned by the captured one, that meets the region anywhere above the captured window means None.
• Foreign windows measured by everything they may paint. That's the union of GetWindowRect and the DWM visible frame, because a self-drawn frame (Electron, Chromium) paints into the border DWM leaves out. The app's own windows keep the visible frame.

Safety for the repair doesn't depend on the center: the caller matches the uncovered part of the band word for word against the recorded identity, refuses parameterised bands, and re-runs the full identity check after the dialog is dismissed.

Adversarial review (independent; it also traced the caller on claude/repair-windows-qualify)

No blockers.

Finding	Severity	Outcome
(a) A foreign window partly over the band next to an owned dialog: None in either z-order; layered overlays and cross-process owner tricks are refused on process ID	—	Holds; tested
A foreign self-drawn frame paints into the border the DWM frame leaves out	Should-fix	Fixed here; tested
(b) A dialog on the right of the band can hide the part that tells two patients apart (a prefix read covering about 57% of the band is accepted)	—	Not a blocker: the full identity check after dismissal protects. It's the caller's prefix rule, in agnostic-repair.
The caller's dismiss click isn't tied to the reported window, and its label gate lets "OK" or "Yes" through on dialogs like "Discard unsaved changes?"	Should-fix (caller)	Passed to agnostic-repair
Any owned popup touching the band, such as a tooltip, now counts as the cause; the caller should require the covered rectangle to span the band from where the read is cut	Should-fix (caller, plus an API change)	Passed to agnostic-repair; returning the intersecting rectangle would change this contract, so it's left for them to ask for
A foreign window reparented with SetParent inside the captured window isn't enumerated	Nit (predates this)	Open

Testing

tests/test_win_agent_server.py and tests/test_windows_backend.py: 171 passed. New tests:

• an owned dialog over part of the region is reported;
• the topmost owned window is reported;
• a foreign window beside an owned dialog gives None in either order;
• a foreign self-drawn frame reaching the band gives None.

The real-VM probe from #1727 still applies: it showed an owned dialog reported and a foreign Notepad refused.