fix(desktop): re-apply UI zoom on show/restore, scoped to chat windows (supersedes #61245)

[OutThisLife]

Summary

Supersedes #61245.

On Windows, Chromium drops webContents zoom on minimize→restore, so the UI snapped back to 100% while Settings still read 125% (#61081). Zoom was only reasserted on the main window's did-finish-load — never on show/restore, and never for secondary session windows.

This reasserts the persisted zoom on show + restore + first load, wired once in wireCommonWindowHandlers so the main window and session windows share the fix.

What this changes vs #61245

#61245 wired the reassert through wireCommonWindowHandlers, which is also used by the pet overlay — the open question Gille raised in the report thread. Letting the pet inherit global UI zoom is a bug, not a nicety:

• The overlay sizes its own OS window to fit the sprite in unzoomed CSS px (overlayWindowSize → setBounds). setZoomLevel scales rendered content but not window bounds, so at 125% the sprite renders larger than the window that contains it and gets cropped at the edges (breaking that helper's own "never cropped by the window edge" invariant; the right:0/top:0 mail button can clip off too).
• The pet already has its own scale system (Alt+wheel gesture + settings slider); global zoom double-scales it and desyncs the fit math.
• The overlay shares the renderer origin (…/index.html?win=overlay), so it reads the same hermes:desktop:zoomLevel key — fix(desktop): re-apply UI zoom after minimize/restore on Windows #61245 would newly pull the main window's 125% into the mascot on spawn.

So zoom is now opt-out: wireCommonWindowHandlers(win, { zoom: false }) for the pet overlay; chat windows keep it on. (Click-through alpha hit-testing itself stays correct — it's all one CSS-px space — but window-fit + the screen/CSS coordinate mixing in drag/pop-out is where zoom bites.)

Files

• electron/zoom.ts — installZoomReassertOnWindowEvents + ZOOM_REASSERT_WINDOW_EVENTS (from fix(desktop): re-apply UI zoom after minimize/restore on Windows #61245).
• electron/main.ts — wireCommonWindowHandlers(win, { zoom }) gate; pet passes { zoom: false }; drop the now-redundant restorePersistedZoomLevel(mainWindow) in createWindow (shared helper handles it).
• electron/zoom.test.ts — fix(desktop): re-apply UI zoom after minimize/restore on Windows #61245's pure-helper tests + a scope assertion (pet opts out, chat windows keep zoom, no double-restore in createWindow).

Test plan

• npx tsx --test electron/zoom.test.ts → 10 passed
• tsc -p apps/desktop --noEmit → no errors in changed files
• Windows: set UI Scale 125%, minimize→restore → stays 125%; open a session window → inherits 125%; pop out the pet → renders 1× and uncropped

Credit: @HexLab98 (original fix + helper tests), preserved via Co-authored-by. Closes the pet-scope review question from the report thread.