fix(ci): build macOS arm64 with Flutter 3.44 (#16821)

* fix(ci): build macOS arm64 with Flutter 3.44

Flutter 3.24.5's macOS engine can crash in attributedSubstringForProposedRange
with an out-of-bounds range on an empty string (#16817). The fix
(flutter/flutter#153157) landed after 3.24 and was never cherry-picked, and
3.44 has the bounds check. So macOS arm64 now builds with Flutter 3.44.9, the
same way Windows arm64 does: the 3.44 bridge artifact and the shared source
patch script. The script uses GNU `sed -i`, which BSD sed on macOS rejects,
so the step puts GNU sed first on PATH. The 3.24 dropdown patch is skipped,
because 3.44 already has that fix.

macOS x86_64 stays on 3.24.5: 3.44's FlutterMacOS needs macOS 10.15 there,
and the build targets 10.14. The Dart tests move to the x86_64 job, so CI
still runs them against the 3.24.5 sources that most platforms ship.

Refs #16817

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* fix(ci): keep CocoaPods on macOS arm64 and run Dart tests on both arches

Flutter 3.44 turns on Swift Package Manager by default. On the first
`flutter build macos` it would migrate Runner.xcodeproj and Runner.xcscheme,
and build file_selector_macos, path_provider_foundation, url_launcher_macos
and video_player_avfoundation through SwiftPM while the other 12 plugins stay
on CocoaPods. If the migration fails, the build fails. All 16 macOS plugins
still ship a podspec, so turning SwiftPM off keeps arm64 on the CocoaPods-only
path the 3.24.5 build uses, and this change only swaps the engine.

The Dart tests now run on both macOS jobs: x86_64 covers the 3.24.5 sources
most platforms ship, and arm64 covers the patched 3.44 sources it ships.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* ci: update comments that still call Windows arm64 the only Flutter 3.44 build

The FLUTTER_WINDOWS_ARM_VERSION note, the Windows source-patch step and the
header of apply_flutter_3.44_source_patches.sh still said Windows arm64 is
the only Flutter 3.44 target. They now mention macOS arm64 too, and the
script header records that macOS needs GNU sed for its `sed -i` calls.
Comments only.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* test: make test_RustDesk_interval_sleep deterministic

The test recorded tick times as wall-clock seconds, rounded to the nearest
second, and asserted all 5 were unique. If the runner stalled for close to a
second, two correct ticks rounded to the same value and the test failed
(macOS arm64 CI on #16821: left 5, right 4).

It now runs on tokio's paused clock and checks what ThrottledInterval
guarantees: ticks are at least 0.9 * period apart. A plain tokio interval
bursts its missed ticks with no gap, so a lost throttle still fails. This
needs tokio's test-util feature for the existing dev-dependency. It adds no
crates, so Cargo.lock is unchanged.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

.github/workflows/bridge.yml

@@ -25,7 +25,7 @@ jobs:
               flutter-version: "3.22.3",
               artifact-name: "bridge-artifact",
             }
-          # Dedicated bridge for the Windows arm64 build (Flutter 3.44); runs in parallel.
+          # Dedicated bridge for the Windows and macOS arm64 builds (Flutter 3.44); runs in parallel.
           - {
               target: x86_64-unknown-linux-gnu,
               os: ubuntu-22.04,
@@ -92,8 +92,8 @@ jobs:
             # Default Flutter 3.22.3: extended_text 14 needs a newer Dart, so downgrade for resolution.
             sed -i -e 's/extended_text: 14.0.0/extended_text: 13.0.0/g' flutter/pubspec.yaml
           else
-            # Flutter 3.44 bridge for Windows arm64: match that build's source/pubspec state so the
-            # generated *.freezed.dart compiles against the same Flutter/freezed it resolves.
+            # Flutter 3.44 bridge for Windows/macOS arm64: match those builds' source/pubspec state so
+            # the generated *.freezed.dart compiles against the same Flutter/freezed they resolve.
             bash .github/patches/apply_flutter_3.44_source_patches.sh
           fi
           pushd flutter && flutter pub get && popd