Phase 5.6A: explicit component enablement bootstrap

[josiahking]

Summary

Implements Phase 5.6A — Explicit Component Definitions and Enablement Bootstrap.

Adds:

• shared experimental ComponentDefinition
• package-specific ModuleDefinition and PluginDefinition
• application-controlled component enablement through evolve.components.enabled
• Core ComponentBootstrapper
• validation-before-entry-point-creation
• graph resolution before lifecycle binding
• exact declaration identity preservation
• ApplicationKernel bootstrap integration
• attributed internal bootstrap failures

Behavior

• discovered components are disabled unless explicitly enabled
• disabled components remain inert
• all enabled definitions validate before any entry point is created
• graph validation runs before entry-point creation
• existing dependency/capability graph rules remain authoritative
• existing Phase 5.5 lifecycle coordinator remains the runtime lifecycle mechanism
• no Composer metadata discovery is included yet; that is Phase 5.6B
• no runtime/per-request enablement
• no Core dependency on Module or Plugin

Validation

Committed-ref SHA:

dafe03cf3ad218d798ee1dcb86d0d05b65c6ed05

Passed:

• Composer strict validation
• release package validation
• deterministic package split validation
• prerelease consumer validation
• Architecture + Documentation policy
• Deptrac
• PHPStan
• PHP-CS-Fixer
• full PHPUnit
• security audit
• locked dependency licence policy

Full PHPUnit:

446 tests, 1850 assertions

Architecture + Documentation:

192 tests, 7286 assertions