[E-8] Performance Validation for GA

[LennyObez]

Epic | P2 | Risk: Medium | Effort: M | Release: 1.0.0

No ORM benchmarks exist. Performance budgets defined in ADR-0012 need to be locked and validated.

Scope:

• Create ORM benchmark suite
• Validate all performance budgets from ADR-0012
• Lock performance baselines for GA

Acceptance criteria:

• ORM benchmarks exist and pass
• All ADR-0012 performance budgets validated
• Baselines locked and documented

[LennyObez]

Progress update: Expanded performance budgets implemented in #368 (commit 957a8dd5).

• 30 budget keys defined (up from 11) with tiered enforcement (Tier A hard gate, Tier B nightly, Tier C RC gate)
• 5 PHPBench benchmark classes: CryptoBench, AuditBench, SessionBench, EndToEndBench, MemoryProfileBench
• Runtime-specific budgets for FPM and persistent runtimes
• Pipeline manifest governance with SHA-256 integrity checks
• Fresh-process peak memory measurement

Remaining for this epic: ORM benchmarks (#302) and final GA baseline lock.