fix(profiling): respect ZAI_CONFIG_ORIGIN_DEFAULT for agent endpoint detection

[Leiyks]

Description

Since a3409cd78, DD_AGENT_HOST and DD_TRACE_AGENT_PORT have non-empty defaults ("localhost" / 8126). The PHP tracer already filters these with ZAI_CONFIG_ORIGIN_DEFAULT checks, but the Rust profiling code was not updated — causing agent_host() and trace_agent_port() to return Some(...) unconditionally and bypass the Unix socket fallback that SSI environments rely on.

Fix: adds ddog_php_prof_config_is_set_by_user() (checks name_index != ZAI_CONFIG_ORIGIN_DEFAULT) and gates both functions on it.

Also pins cargo install cbindgen to --version 0.29.0 --locked to avoid getrandom v0.4.1 pulling in edition2024 support, which requires Cargo ≥ 1.85 (container is on 1.84.1).

Reviewer checklist

• Test coverage seems ok.
• Appropriate labels assigned.

[datadog-datadog-prod-us1]

⚠️ Tests

✨ Fix all issues with BitsAI or with Cursor

⚠️ Warnings

🧪 1028 Tests failed

testSearchPhpBinaries from integration.DDTrace\Tests\Integration\PHPInstallerTest (Datadog) (Fix with Cursor)

Risky Test
phpvfscomposer://tests/vendor/phpunit/phpunit/phpunit:52

testSimplePushAndProcess from laravel-58-test.DDTrace\Tests\Integrations\Laravel\V5_8\QueueTest (Datadog) (Fix with Cursor)

DDTrace\Tests\Integrations\Laravel\V5_8\QueueTest::testSimplePushAndProcess
Test code or tested code printed unexpected output: spanLinksTraceId: 69a0473300000000a106d609a5ea62c4
tid: 69a0473300000000
hexProcessTraceId: a106d609a5ea62c4
hexProcessSpanId: a7a511e14eaf8dac
processTraceId: 11603196826893312708
processSpanId: 12080081234876665260

phpvfscomposer://tests/vendor/phpunit/phpunit/phpunit:106

testSimplePushAndProcess from laravel-8x-test.DDTrace\Tests\Integrations\Laravel\V8_x\QueueTest (Datadog) (Fix with Cursor)

DDTrace\Tests\Integrations\Laravel\V8_x\QueueTest::testSimplePushAndProcess
Test code or tested code printed unexpected output: spanLinksTraceId: 69a0478100000000f54195369fb3855e
tid: 69a0478100000000
hexProcessTraceId: f54195369fb3855e
hexProcessSpanId: a07e8680c9004fdd
processTraceId: 17672570474618651998
processSpanId: 11564828780820189149

View all

ℹ️ Info

❄️ No new flaky tests detected

_{This comment will be updated automatically if new data arrives.
🔗 Commit SHA: a1903e7 | Docs | Datadog PR Page | Was this helpful? Give us feedback!}

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 62.08%. Comparing base (07b618a) to head (a1903e7).

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3677      +/-   ##
==========================================
- Coverage   62.19%   62.08%   -0.12%     
==========================================
  Files         141      141              
  Lines       13352    13352              
  Branches     1746     1746              
==========================================
- Hits         8304     8289      -15     
- Misses       4256     4270      +14     
- Partials      792      793       +1     

see 3 files with indirect coverage changes

---

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[pr-commenter]

Benchmarks [ profiler ]

Benchmark execution time: 2026-02-26 13:20:34

Comparing candidate commit a1903e7 in PR branch leiyks/fix-ssi-tests with baseline commit 07b618a in branch master.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 29 metrics, 7 unstable metrics.

[morrisonlevi]

The profiling parts look good to me. Not sure why the package-oci jobs failed, which should be investigated before merging (but not necessarily fixed, depends if it's related or not).

[morrisonlevi]

package-oci failures are unrelated. Merging.