Add cross-framework comparator foundation

[josiahking]

Summary

• add isolated comparator fixtures for EvolvePHP, Laravel, Symfony, Slim and Phalcon
• define a stable cross-framework scenario matrix for boot, routing, middleware, not-found and repeated-warm requests
• separate execution-environment identity from framework fixture identity
• add comparator correctness smoke validation and deterministic Phalcon availability handling
• keep all comparator dependencies isolated from production packages and the application skeleton

Validation

• root quality: 679 tests / 2456 assertions / 1 skipped
• architecture: 87 tests / 7830 assertions
• documentation: 136 tests / 2527 assertions
• benchmark suite: 48 tests / 301 assertions
• comparator correctness smoke passed for EvolvePHP, Laravel 13.29.0, Symfony 8.1.5 and Slim 4.15.2
• Phalcon correctly reports unavailable when ext-phalcon is not installed
• release package validation passed for all seven packages
• deterministic package split validation passed for all seven packages
• skeleton create-project validation passed
• prerelease consumer validation passed
• supply-chain validation passed

Scope

Benchmark and comparator infrastructure only.

No production package Composer manifests, application skeleton dependencies, or CI workflows are changed.

Local comparator results remain non-canonical; authoritative cross-framework performance measurements require the documented controlled PHP 8.4 benchmark environment.