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 ba85c3b

[codecov]

Codecov Report

❌ Patch coverage is 87.50000% with 4 lines in your changes missing coverage. Please review.
⚠️ Please upload report for BASE (main@c1254d8). Learn more about missing BASE report.

Files with missing lines	Patch %	Lines
Sources/Sentry/SentryTracePropagation.m	81.818%	4 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff            @@
##             main     #6356   +/-   ##
========================================
  Coverage        ?   86.865%           
========================================
  Files           ?       441           
  Lines           ?     37277           
  Branches        ?     17345           
========================================
  Hits            ?     32381           
  Misses          ?      4855           
  Partials        ?        41           

Files with missing lines	Coverage Δ
Sources/Sentry/SentryNetworkTracker.m	99.732% <100.000%> (ø)
Sources/Sentry/SentryOptions.m	97.241% <100.000%> (ø)
Sources/Sentry/SentyOptionsInternal.m	99.671% <100.000%> (ø)
Sources/Sentry/SentryTracePropagation.m	84.931% <81.818%> (ø)

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[github-actions]

Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	1219.76 ms	1255.91 ms	36.16 ms
Size	23.75 KiB	995.62 KiB	971.87 KiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
fc05805	1220.63 ms	1252.16 ms	31.54 ms
b9aacb6	1230.42 ms	1251.00 ms	20.58 ms
d8b2303	1231.53 ms	1249.89 ms	18.35 ms
1339919	1214.82 ms	1238.98 ms	24.16 ms
ac4739e	1236.55 ms	1258.89 ms	22.34 ms
b714cb9	1224.71 ms	1238.04 ms	13.33 ms
d157d83	1228.02 ms	1252.47 ms	24.45 ms
aff3b66	1229.53 ms	1263.08 ms	33.55 ms
7d88965	1228.86 ms	1248.53 ms	19.67 ms
30f4e4c	1213.21 ms	1250.29 ms	37.08 ms

App size

Revision	Plain	With Sentry	Diff
fc05805	23.75 KiB	908.02 KiB	884.27 KiB
b9aacb6	23.75 KiB	913.64 KiB	889.89 KiB
d8b2303	23.75 KiB	908.02 KiB	884.27 KiB
1339919	23.75 KiB	919.70 KiB	895.95 KiB
ac4739e	23.75 KiB	872.67 KiB	848.92 KiB
b714cb9	23.75 KiB	858.69 KiB	834.93 KiB
d157d83	23.75 KiB	928.85 KiB	905.10 KiB
aff3b66	23.75 KiB	978.53 KiB	954.78 KiB
7d88965	23.75 KiB	994.72 KiB	970.98 KiB
30f4e4c	23.75 KiB	879.24 KiB	855.50 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
fe4d5d5	1237.80 ms	1253.33 ms	15.53 ms
786f095	1231.33 ms	1261.23 ms	29.90 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
fe4d5d5	23.75 KiB	990.49 KiB	966.74 KiB
786f095	23.75 KiB	988.54 KiB	964.80 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