fix(mobile): play short-delay animation frames at browser speed - #9432

The two follow-ups from the pre-review of [#9432 GIF frame
timing](#9432), rebased onto main now
that it has landed.

**iOS reaction details sheet.** The sheet decodes custom emoji natively
(`NativeMessageImageLoader.decode`) and timed each frame as `max(0.02,
delay)`, so with [#9432 GIF frame
timing](#9432) a GIF with 0 or 1 cs
delays plays at 100 ms per frame in the timeline chip but 20 ms per
frame in the sheet opened from it. The decoder now shows frames of 10 ms
or less for 100 ms, as browsers and `MediaImageProvider` do, and keeps
longer frames as written. The 20 ms floor goes with it: browsers keep 11
to 19 ms frames as written too.

**Provider-level test.** The existing tests call
`withBrowserFrameTiming` directly, so removing the provider's call to it
left the suite green. A new test resolves a GIF through
`MediaImageProvider` with a mock HTTP client and pumps the scheduler's
app frames at explicit timestamps: the 10 ms first frame is still
showing at 50 ms and is replaced at 100 ms.

### Regressions

None expected. The sheet already summed the frame delays into one
`UIImage.animatedImage` duration, so only the per-frame value changes,
and only for frames of 10 ms or less, which ran at 20 ms before. Still
images and longer frames decode as before. The Dart test drives frame
callbacks with explicit timestamps rather than waiting on wall-clock
time.

### Validation

Added tests: `NativeMessageImageLoaderDecodeTests` in RunnerTests (a 0,
1, 2, 5 cs GIF decodes to a 0.27 s animation; a one-frame GIF stays
still) and `withBrowserFrameTiming is applied to the frames
MediaImageProvider plays` in `media_image_test.dart`, which fails when
the provider's call is removed (the second frame shows at 50 ms).

Full mobile suite: 4,780 tests passed. `flutter analyze`: no issues.
RunnerTests `NativeMessageImageLoaderDecodeTests` and
`NativeReactionDetailsTests`: all five pass on an iPhone 17 simulator
(Xcode build-for-testing of the Debug simulator app). No full-app run:
the change is one delay value in a decoder and is covered by the unit
tests above.

Signed-off-by: Tom Brow <[email protected]>
Co-authored-by: Tom Brow <[email protected]>
Co-authored-by: judge <7615ec4b7ddf99f0bb48e913297f99f8f772d289a1c9ef54e1d906dd55a93ba8@sprout-oss.stage.blox.sqprod.co>

Co-authored-by: mboston.Engineer <932d3b6ebea6cc83e091551ae46d1c7e7f8f7d0fa8e9cef5e6facc8544af413b@buzz.block.builderlab.xyz>

* origin/main:
  fix(mobile): require Builderlab consent for existing identities (#8823)
  feat(mobile): use HTTP/2 on iOS through app-wide URLSessions (#8897)
  fix(relay): publish a git push only when refs changed; check the protocol by refinement (#9425)
  fix(mobile): show shared chats under Solo (#9348)
  chore(release): release Buzz Desktop version 0.5.29 (#9456)
  feat(mobile): render messages with gpt_markdown 1.3.4 plusparse (#8945)
  fix(acp): bound observer retention by bytes (#7987) (#9436)
  Tune release codegen for faster/smaller binaries (#9434)
  feat(desktop): add dismissible banner pointing to the new buzz app (#9379)
  fix(mobile): keep publishing presence while the app is open (#9441)
  feat(mobile): share into Buzz from the iOS share sheet (#9433)
  fix(mobile): qualify every namesake mention and keep authored mention casing (#9325)
  fix(mobile): match browser GIF timing in the iOS reaction sheet (#9437)
  fix(mobile): play short-delay animation frames at browser speed (#9432)
  buzz-search: read profile names without the profile_name_fields function (#9397)
  buzz-db: build the community deletion lock key in Rust (#9396)
  fix(cli): pair for the active community, skip stopped desktops, accept a bare relay host (#9417)
  test(mobile): run push tests without a gateway dart-define (#9423)
  fix(mobile): never pop Home when archiving from channel settings (#9387)
  perf(acp): reduce observer CPU and lock overhead (#9381)

Signed-off-by: Matthew Boston <[email protected]>

…count-backfill

Co-authored-by: mboston.Engineer <932d3b6ebea6cc83e091551ae46d1c7e7f8f7d0fa8e9cef5e6facc8544af413b@buzz.block.builderlab.xyz>

* bostonaholic--agent-reply-count:
  fix(mobile): require Builderlab consent for existing identities (#8823)
  feat(mobile): use HTTP/2 on iOS through app-wide URLSessions (#8897)
  fix(relay): publish a git push only when refs changed; check the protocol by refinement (#9425)
  fix(mobile): show shared chats under Solo (#9348)
  chore(release): release Buzz Desktop version 0.5.29 (#9456)
  feat(mobile): render messages with gpt_markdown 1.3.4 plusparse (#8945)
  fix(acp): bound observer retention by bytes (#7987) (#9436)
  Tune release codegen for faster/smaller binaries (#9434)
  feat(desktop): add dismissible banner pointing to the new buzz app (#9379)
  fix(mobile): keep publishing presence while the app is open (#9441)
  feat(mobile): share into Buzz from the iOS share sheet (#9433)
  fix(mobile): qualify every namesake mention and keep authored mention casing (#9325)
  fix(mobile): match browser GIF timing in the iOS reaction sheet (#9437)
  fix(mobile): play short-delay animation frames at browser speed (#9432)
  buzz-search: read profile names without the profile_name_fields function (#9397)
  buzz-db: build the community deletion lock key in Rust (#9396)
  fix(cli): pair for the active community, skip stopped desktops, accept a bare relay host (#9417)
  test(mobile): run push tests without a gateway dart-define (#9423)
  fix(mobile): never pop Home when archiving from channel settings (#9387)
  perf(acp): reduce observer CPU and lock overhead (#9381)

Signed-off-by: Matthew Boston <[email protected]>