refactor: Separate CLI presentation from core business logic

Complete architectural separation of concerns implementing clean layered design:

• Services Layer: Pure business logic isolated from presentation
  - WorkspaceService: TDD workspace operations
  - IssueService: Issue management and creation
  - ProjectService: Project management and milestones
  - ExportService: Unix-friendly data export

• CLI Layer: Clean presentation with command/presenter separation
  - Commands delegate to services for all business operations
  - Presenters handle formatted output and error messaging
  - Framework provides unified interface

• Benefits:
  - Eliminates mixed concerns in 943-line CLI monolith
  - Enables easier testing and maintenance
  - Preserves all existing functionality and Unix pipeline compatibility
  - Provides foundation for future CLI development

Resolves issue #20: CLI separation from core logic

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

cli/__init__.py

@@ -0,0 +1,20 @@
+"""
+CLI presentation layer.
+
+This package handles all CLI-specific concerns:
+- Argument parsing and validation
+- Output formatting and presentation
+- User interaction and feedback
+- Error handling and display
+
+The CLI layer delegates business logic to services and focuses purely on
+presentation and user interface concerns.
+"""
+
+from .core import CLIFramework
+from .presenters import *
+from .commands import *
+
+__all__ = [
+    'CLIFramework'
+]