Implement Phase 3 improvements from IMPROVEMENTS.md

[swedishkid]

This commit implements all Phase 3 advanced features:

1. Conditional Execution:

   • OS conditions (windows, linux, osx/macos)
   • Environment variable conditions (value matching and existence check)
   • File existence conditions (fileExists and fileNotExists)
   • ConditionEvaluator service for evaluating conditions

2. Task Hooks:

   • preTasks: Run tasks before the main task
   • postTasks: Run tasks after successful main task completion
   • Validation for hook task references

3. Profile Support:

   • Define profiles with variables and environment overrides
   • --profile CLI option to select active profile
   • Profile env applied before task-specific env

4. Task Caching:

   • Cache based on input file patterns (glob matching)
   • Output directory validation
   • TTL (time-to-live) expiration support
   • --no-cache CLI option to bypass caching
   • CacheManager service with hash-based validation

5. Plugin System:

   • ITaskTypeProvider interface for custom task types
   • PluginLoader service for loading external assemblies
   • RegisterProvider for programmatic registration
   • Automatic task type routing based on type field

Also includes:

• Comprehensive unit tests for all Phase 3 features
• Updated TaskValidator for new properties
• Updated init templates with Phase 3 examples
• Updated IMPROVEMENTS.md to mark Phase 3 complete

https://claude.ai/code/session_01RwwnUKemQP2JHn8afHCE5J