[mforce]

Step 0 of #1271. This PR only measures: it changes no test and no product code.

Same-day runs of the integration leg range from 10.7 to 16.6 minutes. The console log gives no per-test start or end times and does not name the CPU. Steps 1 to 3 of #1271 need both to prove their effect on CI.

What the integration leg records now

• A Show runner CPU step prints Model name and CPU(s) from lscpu. A step-level if limits it to the integration leg. The job has no new if, continue-on-error or fail-fast change (CI: measure where Build and test's 10 minutes go, and what the backend suite covers #775).
• The dotnet test command for the integration leg gets --logger "trx;LogFileName=integration.trx". The blame-hang arguments stay as they are, and the other three legs expand to the same command as before.
• An Upload integration timings step uploads TestResults/integration.trx as the integration-trx artifact, kept 14 days, whether the tests pass or fail (always()).

The trx holds test names, timings, outcomes, failure messages and stack traces. xUnit v2 does not capture per-test console output, and no integration test uses ITestOutputHelper. The trx's run-level StdOut repeats the test process console (Testcontainers and host log lines), and the Test step's public log already prints those lines. The disposable-credential argument of the existing hang-diagnostics upload covers this artifact too.

Not included:

• A step-summary table. tools/test-timing/summarize.py also needs run.json, console.log and Docker events, so it cannot run on the trx alone.
• CLUCKWORK_TEST_TIMING. It only prints fixture phase timings to the console, and the A/B does not use them.

Verification

• ci.yml parses with yaml.safe_load.
• SchemaDocsTests and SolutionTestProjectSplitTests read ci.yml. Run locally with a filter: 5/5 pass.
• SecurityHeadersTests, run locally with the leg's blame and results-directory arguments plus the new logger: 8/8 pass. The trx lands at <results-dir>/integration.trx, the path the upload names, and every UnitTestResult has startTime and endTime.

Part of #1271

On this PR's CI run

Run 38290032941 at e811bdc passed every job.

• The integration leg printed Model name: AMD EPYC 7763 64-Core Processor and CPU(s): 4. The leg took 16m39s.
• The integration-trx artifact (1.2 MB zipped) holds 307 classes. The serial integration collection (128 classes) ran from 17.0 s to 902.5 s, and no other test was running for 509 s of that span. Its largest classes were OAuthFailClosedTests (161 s), McpAuthorizationTests (86 s), RecordDailyEntryToolTests (75 s), McpToolErrorTests (72 s) and AccountLifecycleCommandTests (60 s).