feat: Add propagating of traceparent

[philipphofmann]

📜 Description

Added support for OTel/W3C trace propagation by introducing a new option enablePropagateTraceparent that controls whether the SDK adds the W3C traceparent HTTP header to outgoing requests.

Docs PR getsentry/sentry-docs#15159

💡 Motivation and Context

Fixes GH-6017

💚 How did you test it?

Added unit tests to verify the traceparent header is correctly added when the feature is enabled and not added when disabled. Also tested that existing headers aren't overridden.

📝 Checklist

You have to check all boxes before merging:

• I added tests to verify the changes.
• No new PII added or SDK only sends newly added PII if sendDefaultPII is enabled.
• I updated the docs if needed.
• I updated the wizard if needed.
• Review from the native team if needed.
• No breaking change or entry added to the changelog.
• No breaking change for hybrid SDKs or communicated to hybrid SDKs.

[philipphofmann]

• feat: Add propagating of traceparent #6356 👈 (View in Graphite)
• ref: Remove SentrySDK from trace propagation class #6354
• test: Extract isTargetTests to own test class #6352
• ref: Move trace propagation to its own class #6337
• main

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[github-actions]

	Messages
📖	Do not forget to update Sentry-docs with your feature once the pull request gets approved.

Generated by 🚫 dangerJS against 1b58355

[codecov]

❌ 3 Tests Failed:

Tests completed	Failed	Passed	Skipped
4019	3	4016	31

View the top 3 failed test(s) by shortest run time

iOS_Swift_UITests.LaunchUITests::testCaptureException

Stack Traces | 0s run time

.../iOS-Swift/iOS-Swift-UITests/LaunchUITests.swift:43 - Failed to Error Domain=com.apple.dt.XCTest.XCTFuture Code=1000 "Timed out while evaluating UI query." UserInfo={NSLocalizedDescription=Timed out while evaluating UI query.}: Timed out while evaluating UI query.

iOS_Swift_UITests.LaunchUITests::testCheckSlowAndFrozenFrames

Stack Traces | 0s run time

.../iOS-Swift/iOS-Swift-UITests/LaunchUITests.swift:66 - Failed to Error Domain=com.apple.dt.XCTest.XCTFuture Code=1000 "Timed out while evaluating UI query." UserInfo={NSLocalizedDescription=Timed out while evaluating UI query.}: Timed out while evaluating UI query.

iOS_Swift_UITests.LaunchUITests::testLoremIpsum

Stack Traces | 0s run time

.../iOS-Swift/iOS-Swift-UITests/LaunchUITests.swift:14 - Failed to Error Domain=com.apple.dt.XCTest.XCTFuture Code=1000 "Timed out while evaluating UI query." UserInfo={NSLocalizedDescription=Timed out while evaluating UI query.}: Timed out while evaluating UI query.

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[github-actions]

Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	1230.08 ms	1262.12 ms	32.03 ms
Size	23.75 KiB	1005.85 KiB	982.10 KiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
570f725	1206.00 ms	1238.96 ms	32.96 ms
ab0ba7e	1216.08 ms	1242.40 ms	26.31 ms
a6f5396	1211.81 ms	1245.63 ms	33.82 ms
6502818	1229.08 ms	1245.46 ms	16.37 ms
04ff3ec	1220.71 ms	1253.86 ms	33.15 ms
c122943	1210.94 ms	1233.78 ms	22.84 ms
59fc426	1240.49 ms	1256.94 ms	16.45 ms
397b9c9	1230.23 ms	1249.29 ms	19.06 ms
51b7dd3	1235.06 ms	1258.21 ms	23.15 ms
2a6f451	1212.89 ms	1237.45 ms	24.56 ms

App size

Revision	Plain	With Sentry	Diff
570f725	23.74 KiB	913.38 KiB	889.63 KiB
ab0ba7e	23.75 KiB	904.54 KiB	880.79 KiB
a6f5396	23.75 KiB	989.12 KiB	965.38 KiB
6502818	23.75 KiB	959.45 KiB	935.70 KiB
04ff3ec	23.75 KiB	880.26 KiB	856.52 KiB
c122943	23.74 KiB	926.65 KiB	902.90 KiB
59fc426	23.75 KiB	920.64 KiB	896.89 KiB
397b9c9	23.75 KiB	959.44 KiB	935.70 KiB
51b7dd3	23.75 KiB	913.26 KiB	889.52 KiB
2a6f451	23.75 KiB	913.13 KiB	889.38 KiB

Previous results on branch: feat_add_propagating_of_traceparent

Startup times

Revision	Plain	With Sentry	Diff
fec69f5	1233.02 ms	1266.88 ms	33.85 ms
1c5ce84	1219.49 ms	1249.06 ms	29.57 ms
ed645d9	1219.76 ms	1255.91 ms	36.16 ms
786f095	1231.33 ms	1261.23 ms	29.90 ms
fe4d5d5	1237.80 ms	1253.33 ms	15.53 ms
dea0f9c	1227.83 ms	1262.15 ms	34.32 ms

App size

Revision	Plain	With Sentry	Diff
fec69f5	23.75 KiB	987.44 KiB	963.69 KiB
1c5ce84	23.75 KiB	987.45 KiB	963.70 KiB
ed645d9	23.75 KiB	995.62 KiB	971.87 KiB
786f095	23.75 KiB	988.54 KiB	964.80 KiB
fe4d5d5	23.75 KiB	990.49 KiB	966.74 KiB
dea0f9c	23.75 KiB	990.65 KiB	966.90 KiB

[noahsmartin]

It looks like you might have ran the api file generation using Xcode 26, CI uses 16.4 so it won't pass CI unless you use that. This was because Xcode 26 doesn't include the objc public API (only Swift)

[github-actions]

🚨 Detected changes in high risk code 🚨

High-risk code can easily blow up and is hard to test. We had severe bugs in the past. Be extra careful when changing these files, and have an extra careful look at these:

• Sources/Sentry/SentryNetworkTracker.m