Preset system: Add hook system for post-install automation

[mbachorik]

Summary

Port the hook system from extensions to presets, enabling post-install automation and preset composition.

Context

Extensions have a sophisticated hook system (extensions.py:1509-1884):

• Event-based hooks (after_spec, after_tasks, etc.)
• Conditional hook execution
• Config-based hook conditions
• Hook lifecycle management

Presets have no hook support.

Requirements

• Define relevant hook events for presets (e.g., after_install, after_resolve)
• Port HookExecutor pattern to PresetManager
• Add hooks section to preset manifest
• Implement hook registration/execution lifecycle

Related

• Reverse parity: extensions → presets