Zoom on a phone was only the +/- buttons; the pinch people try first did
nothing. usePinchZoom tracks a two-finger gesture on the viewer's media area
and scales from the zoom it started at (clamped 1×–5×, snapping back to
exactly 1× when released near it, so one-finger swipe navigation re-arms).
The area gets touch-action: none so the browser doesn't zoom the page
instead. One-finger swipe and pan already ignore multi-touch.
Verified on an emulated Pixel 7 with CDP two-point touch: spread 80→200 px
gives 250 %, closing to 120 px gives 150 %, closing fully returns to 100 %,
and a one-finger swipe afterwards still moves 2/2 → 1/2.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PPmy3tPq869XDW4njjVaKA
