ref: Convert SentrySwiftAsyncIntegration to Swift

[noahsmartin]

Convert this simple integration to Swift

#skip-changelog

Closes #6933

[github-actions]

Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	1222.38 ms	1256.91 ms	34.53 ms
Size	24.14 KiB	1.01 MiB	1013.10 KiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
0ee162c	1226.90 ms	1261.72 ms	34.83 ms
7f26f16	1220.62 ms	1255.04 ms	34.42 ms
5290541	1216.38 ms	1249.56 ms	33.18 ms
319fb1e	1219.48 ms	1242.69 ms	23.21 ms
0f410ad	1193.34 ms	1255.49 ms	62.15 ms
b6f8eb3	1217.94 ms	1246.57 ms	28.63 ms
e8f9a1d	1229.02 ms	1264.17 ms	35.15 ms
37238de	1236.00 ms	1267.80 ms	31.80 ms
0ecea77	1191.47 ms	1216.12 ms	24.65 ms
1655116	1220.72 ms	1260.58 ms	39.85 ms

App size

Revision	Plain	With Sentry	Diff
0ee162c	23.75 KiB	933.33 KiB	909.58 KiB
7f26f16	23.75 KiB	1.02 MiB	1016.66 KiB
5290541	24.14 KiB	1.01 MiB	1015.38 KiB
319fb1e	23.75 KiB	1019.18 KiB	995.43 KiB
0f410ad	24.14 KiB	1.01 MiB	1014.82 KiB
b6f8eb3	23.75 KiB	988.70 KiB	964.95 KiB
e8f9a1d	23.75 KiB	969.78 KiB	946.04 KiB
37238de	23.75 KiB	963.18 KiB	939.43 KiB
0ecea77	24.15 KiB	1.01 MiB	1014.90 KiB
1655116	23.75 KiB	1023.84 KiB	1000.10 KiB

Previous results on branch: swiftAsyncIntegrationSwift

Startup times

Revision	Plain	With Sentry	Diff
46b8841	1222.51 ms	1250.14 ms	27.63 ms
a3f85ea	1214.82 ms	1248.58 ms	33.76 ms
05e34b3	1217.47 ms	1253.78 ms	36.31 ms

App size

Revision	Plain	With Sentry	Diff
46b8841	24.14 KiB	1.02 MiB	1015.89 KiB
a3f85ea	24.14 KiB	1.02 MiB	1015.88 KiB
05e34b3	24.14 KiB	1.02 MiB	1015.88 KiB

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 85.039%. Comparing base (d6ab868) to head (f2d54a0).
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@              Coverage Diff              @@
##              main     #6932       +/-   ##
=============================================
+ Coverage   85.029%   85.039%   +0.009%     
=============================================
  Files          453       453               
  Lines        27635     27639        +4     
  Branches     12144     12145        +1     
=============================================
+ Hits         23498     23504        +6     
+ Misses        4093      3851      -242     
- Partials        44       284      +240     

Files with missing lines	Coverage Δ
Sources/Sentry/SentrySDKInternal.m	85.080% <100.000%> (-0.060%)	⬇️
Sources/Swift/Core/Integrations/Integrations.swift	100.000% <100.000%> (+7.142%)	⬆️
...ces/Swift/Integrations/SwiftAsyncIntegration.swift	100.000% <100.000%> (ø)

... and 37 files with indirect coverage changes

---

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[cursor]

Bug: Global flag not reset when integration disabled on re-initialization

The original Objective-C implementation always called sentrycrashsc_setSwiftAsyncStitching(options.swiftAsyncStacktraces) regardless of the option value, explicitly setting the global stitchSwiftAsync flag to either true or false. The new Swift implementation only calls sentrycrashsc_setSwiftAsyncStitching(true) when enabled and returns nil without calling anything when disabled. If the SDK is re-initialized without calling close() first and swiftAsyncStacktraces changes from true to false, the global flag remains enabled because neither uninstall() is called on the old integration nor is the flag explicitly disabled by the new initialization.