Reset by holding the button, not by tapping it twice

A test user found the reset button, tapped it once and gave up. That is what
the old feedback invited: a first tap brightened the icon and started a ring
draining over 2s, and a draining ring reads as "wait" or "loading", not "press
me again". The one thing that would have said otherwise — a word — is not
available here, because the bar is shared by two players sitting opposite each
other and every word in this app lives inside a panel that rotates to face one
of them.

"Tap this twice" has no wordless vocabulary. "Keep holding" has a very
well-worn one, so reset is now a 975ms hold: a dim track ring appears whole the
moment the finger lands, a bright arc fills over it from 12 o'clock, and
letting go early makes the arc retreat. The retreat is the instruction. A stray
hold is also far less likely than two stray taps inside 2s, so the live game
this was guarding is guarded better than before.

Three things that look incidental and are not:

- Hiding the ring is an opacity that waits out the retreat, not display:none,
  which cut the retreat off at the instant of release — invisible, and it was
  the whole point. The fade has a real duration because a 0s transition with a
  delay may be treated as no transition at all, taking the delay with it.
- width:auto on the ring: .btn svg sets a width for the bar icons, and
  inheriting it against the ring's new height draws an ellipse.
- The ring's transition is exempted from the blanket prefers-reduced-motion
  rule. Collapsing it would fill the ring the instant you touched the button
  and claim the reset was done 975ms before it was. It reports state.

Keyboard, switch and assistive activation cannot hold, and hold-only would have
left those users unable to reset at all, one release after an accessibility
pass. Clicks arriving with detail 0 — no pointer behind them — keep the old
two-presses-within-2s and the draining ring.

Success now sounds: the flag's falling triad, rising instead. Deliberately not
another rising fifth, which sndSwap owns and plays on every handover.

Also corrects a claim in RELEASING.md: the screenshots reproduce near-exactly,
not exactly. Two runs of identical code differ by a 4x13 pixel sliver where the
delay bar's fill edge lands mid-pixel, so a non-empty git diff after re-running
proves nothing on its own.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

RELEASING.md

@@ -116,9 +116,16 @@ python3 tools/screenshots.py
 
 That rewrites all five in
 `fastlane/metadata/android/en-US/images/phoneScreenshots/` at 1170×2532. They
-are rendered from `public_html/index.html` with headless Chromium, not taken on
-a phone, so they reproduce exactly — anything that changes the look of the app
-is a reason to re-run it.
+are rendered from `public_html/index.html` with headless Chromium rather than
+taken on a phone, so anything that changes the look of the app is a reason to
+re-run it.
+
+**Near-exact, not exact.** Two runs of identical code differ by a few bytes in
+shots 1 and 4: a 4×13 pixel sliver at the delay bar's fill edge, where the
+`scaleX` boundary lands mid-pixel and the rasteriser rounds it differently from
+one run to the next. Max channel difference 11, invisible. So a `git diff` after
+re-running is not evidence that anything changed — compare the pixels before
+believing it, and `git checkout` the files back if that sliver is all it is.
 
 The script sets each scene by seeding `localStorage` before the app boots, so
 the app renders its own saved state rather than having the DOM poked from