test: split suites and isolate performance workloads

[gbaudrit]

Summary

Reorganizes the test portfolio into explicit fast, integration, and performance lanes, splits the oversized Management suite into focused processes, and adds CI memory evidence and conservative concurrency limits. Every hosted Management process now remains below the 900 MiB objective on the final GitHub Actions reference run.

Closes #298.
Closes #299.
Closes #300.
Closes #301.
Closes #302.
Closes #303.
Closes #304.
Closes #351.

Changes

• fix(test): enforce Microsoft Testing Platform inputs #306 / Make Microsoft.Testing.Platform validation execute the expected tests #299 — enforces Microsoft Testing Platform solution/project syntax and minimum discovery counts.
• test: define independent validation lanes #307 / Define independent fast, integration, and performance test lanes #300 — introduces independent fast, integration, and performance solution lanes and documents the taxonomy.
• test(management): split core storage and source suites #309 / Split Management core, storage, and source tests into bounded projects #301 — splits Management Core, storage, and source/Pack tests into dedicated assemblies.
• test(management): split hosted test suites #311 / Split hosted Management API, Security, and AEP tests with a lightweight host #302 — splits hosted Management API, Security, and AEP tests; API-only factories avoid unnecessary Razor/static construction.
• test(performance): isolate storage workloads #312 / Isolate storage performance workloads from functional tests #303 — isolates storage benchmarks in a performance project, keeps a bounded functional contention smoke, enriches JSON reports, and adds scheduled/manual workloads.
• ci(test): bound parallelism and report memory #334 / Bound test parallelism and publish duration and memory diagnostics #304 — caps module parallelism, adds discovery safeguards, and publishes privacy-safe per-module duration and memory diagnostics with documented budgets.
• test(management): isolate bootstrap host tests #353 / Keep hosted Management API tests below their memory budget #351 — isolates 23 declarative-bootstrap scenarios from the 43 general Management API tests so their process heaps have independent bounds.

Validation

• Full Release solution build succeeds with 0 warnings and 0 errors.
• Functional inventory: 831 tests across explicit lanes.
• Fast lane: 139/139 passed with at most 4 concurrent modules.
• Integration lane: 692 total, 689 passed, 3 optional skipped, with at most 2 concurrent modules.
• Autonomous AEP SDK: 33/33 passed.
• Management inventory preserved: 255 tests across seven focused projects.
• Final GitHub Actions peak working sets: Sources 535.6 MiB; API 859.7 MiB; Bootstrap 467.0 MiB; Security 834.3 MiB; AEP 430.8 MiB. All remain below the 900 MiB objective; Security exceeds its more conservative 800 MiB advisory budget and remains visible as a non-blocking warning for trend review.
• Local Windows split measurements: API 749.3 MiB for 43 tests; Bootstrap 355.3 MiB for 23 tests.
• SQLite performance smoke and 500-operation full workload pass with 0 errors and machine-readable reports; PostgreSQL is configured for service-backed CI.
• Architecture: 40/40 passed.
• All required GitHub checks pass, including build-and-test, Windows host lifecycle, PostgreSQL storage, container, documentation, dependency review, and CodeQL.
• Desktop and mobile smoke testing not applicable; production behavior is unchanged.

Breaking changes

None.