Use FFI/JNI for captureEnvelope on iOS and Android

[buenaflor]

Step towards #1444

💚 How did you test it?

It's currently hard to mock JNI/FFI calls so we'll be relying on integration tests and verifying that method channel calls are not made anymore for captureEnvelope

Performance improvement is marginal but an improvement nonetheless

---

iOS:
FFI calls (26 samples):
Average ≈ 2 967.4 microseconds

Channel calls (25 samples):
Average ≈ 3 264.5 microseconds

---

Android:
JNI calls (33 samples):
Average ≈ 1 012.8 microseconds

Channel calls (32 samples):
Average ≈ 1 462.5 microseconds

---

📝 Checklist

• I reviewed submitted code
• I added tests to verify changes
• No new PII added or SDK only sends newly added PII if sendDefaultPii is enabled
• I updated the docs if needed
• All tests passing
• No breaking changes

🔮 Next steps

@sentry review

[codecov]

Codecov Report

❌ Patch coverage is 57.89474% with 8 lines in your changes missing coverage. Please review.
✅ Project coverage is 89.29%. Comparing base (de377fd) to head (01ae22f).

Files with missing lines	Patch %	Lines
...tter/lib/src/native/cocoa/sentry_native_cocoa.dart	63.63%	4 Missing ⚠️
...lutter/lib/src/native/java/sentry_native_java.dart	50.00%	4 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3115      +/-   ##
==========================================
+ Coverage   86.77%   89.29%   +2.52%     
==========================================
  Files         131       96      -35     
  Lines        4861     3447    -1414     
==========================================
- Hits         4218     3078    -1140     
+ Misses        643      369     -274     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[github-actions]

iOS Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	1258.76 ms	1274.46 ms	15.70 ms
Size	20.71 MiB	22.45 MiB	1.74 MiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
2cb90b9	1272.90 ms	1285.55 ms	12.66 ms
dbd526b	1244.78 ms	1259.02 ms	14.24 ms
81f83eb	1259.53 ms	1273.39 ms	13.86 ms
73dca78	1246.65 ms	1265.42 ms	18.76 ms
6b69699	1254.80 ms	1273.31 ms	18.52 ms
f761369	1261.69 ms	1277.82 ms	16.12 ms
640ad0c	1241.04 ms	1253.96 ms	12.92 ms
7cfbbd6	1270.63 ms	1285.36 ms	14.72 ms
e45c0e1	1269.08 ms	1278.83 ms	9.75 ms
cc4e375	1253.06 ms	1263.81 ms	10.75 ms

App size

Revision	Plain	With Sentry	Diff
2cb90b9	7.86 MiB	9.54 MiB	1.69 MiB
dbd526b	7.86 MiB	9.44 MiB	1.58 MiB
81f83eb	7.86 MiB	9.44 MiB	1.58 MiB
73dca78	7.86 MiB	9.44 MiB	1.58 MiB
6b69699	7.86 MiB	9.44 MiB	1.58 MiB
f761369	7.86 MiB	9.44 MiB	1.58 MiB
640ad0c	7.86 MiB	9.44 MiB	1.58 MiB
7cfbbd6	7.86 MiB	9.44 MiB	1.58 MiB
e45c0e1	7.86 MiB	9.44 MiB	1.58 MiB
cc4e375	7.86 MiB	9.44 MiB	1.58 MiB

Previous results on branch: enh/ffi-jni-capture-envelope

Startup times

Revision	Plain	With Sentry	Diff
4d265af	1274.31 ms	1284.55 ms	10.24 ms
8243b86	1256.24 ms	1268.31 ms	12.06 ms
5fa2e5f	1233.29 ms	1237.04 ms	3.75 ms
fcdc0a0	1270.39 ms	1282.24 ms	11.86 ms

App size

Revision	Plain	With Sentry	Diff
4d265af	7.86 MiB	9.45 MiB	1.59 MiB
8243b86	7.86 MiB	9.45 MiB	1.59 MiB
5fa2e5f	7.86 MiB	9.45 MiB	1.59 MiB
fcdc0a0	7.86 MiB	9.45 MiB	1.59 MiB

[github-actions]

Android Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	451.48 ms	506.33 ms	54.85 ms
Size	6.54 MiB	7.71 MiB	1.17 MiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
eca355d	485.50 ms	569.85 ms	84.35 ms
6f47800	451.04 ms	509.64 ms	58.60 ms
2cf9161	454.12 ms	512.67 ms	58.55 ms
cc4e375	426.15 ms	482.34 ms	56.19 ms
793f4dc	462.68 ms	544.21 ms	81.53 ms
b6c8720	457.41 ms	519.04 ms	61.63 ms
3615e19	468.38 ms	504.71 ms	36.33 ms
575ebaa	478.00 ms	585.76 ms	107.76 ms
2d34233	470.54 ms	558.90 ms	88.36 ms
9b99523	456.91 ms	490.55 ms	33.64 ms

App size

Revision	Plain	With Sentry	Diff
eca355d	6.54 MiB	7.70 MiB	1.16 MiB
6f47800	6.54 MiB	7.69 MiB	1.15 MiB
2cf9161	6.54 MiB	7.70 MiB	1.16 MiB
cc4e375	6.54 MiB	7.69 MiB	1.15 MiB
793f4dc	6.54 MiB	7.69 MiB	1.15 MiB
b6c8720	6.54 MiB	7.69 MiB	1.15 MiB
3615e19	6.54 MiB	7.70 MiB	1.16 MiB
575ebaa	6.54 MiB	7.69 MiB	1.15 MiB
2d34233	6.54 MiB	7.55 MiB	1.01 MiB
9b99523	6.54 MiB	7.69 MiB	1.15 MiB

Previous results on branch: enh/ffi-jni-capture-envelope

Startup times

Revision	Plain	With Sentry	Diff
8243b86	480.34 ms	499.35 ms	19.01 ms
5fa2e5f	508.60 ms	556.53 ms	47.93 ms
fcdc0a0	504.15 ms	536.24 ms	32.09 ms

App size

Revision	Plain	With Sentry	Diff
8243b86	6.54 MiB	7.71 MiB	1.17 MiB
5fa2e5f	6.54 MiB	7.71 MiB	1.17 MiB
fcdc0a0	6.54 MiB	7.71 MiB	1.17 MiB

[github-actions]

🚨 Detected changes in high risk code 🚨

High-risk code has higher potential to break the SDK and may be hard to test. To prevent severe bugs, apply the rollout process for releasing such changes and be extra careful when changing and reviewing these files:

• flutter/android/src/main/kotlin/io/sentry/flutter/SentryFlutterPlugin.kt