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/commands/workspace.py

@@ -0,0 +1,99 @@
+"""
+Workspace CLI commands.
+"""
+
+from tddai import TddaiError
+from services import WorkspaceService
+from cli.presenters import OutputFormatter, WorkspaceView
+
+
+class WorkspaceCommands:
+    """Commands for workspace operations."""
+
+    def __init__(self):
+        self.service = WorkspaceService()
+
+    def status(self) -> None:
+        """Show current workspace status."""
+        try:
+            summary = self.service.get_workspace_summary()
+            WorkspaceView.show_status(summary)
+        except TddaiError as e:
+            OutputFormatter.exit_with_error(str(e))
+
+    def start_issue(self, issue_number: int) -> None:
+        """Start working on an issue."""
+        try:
+            OutputFormatter.info(f"Starting work on issue #{issue_number}...")
+            OutputFormatter.info(f"Fetching issue #{issue_number} details...")
+
+            workspace_info = self.service.start_issue_workspace(issue_number)
+            summary = self.service.get_workspace_summary()
+            WorkspaceView.show_start_success(summary)
+
+        except TddaiError as e:
+            if "Already working on" in str(e):
+                OutputFormatter.warning(str(e))
+                print("   Run 'make tdd-finish' first or 'make tdd-status' to see details")
+                OutputFormatter.exit_with_error("Cannot start new workspace", 1)
+            else:
+                OutputFormatter.exit_with_error(str(e))
+
+    def finish_issue(self) -> None:
+        """Finish current issue workspace."""
+        try:
+            issue_number = self.service.finish_current_workspace()
+            if issue_number is None:
+                OutputFormatter.error("No active issue workspace")
+                print("   Nothing to finish")
+                OutputFormatter.exit_with_error("", 1)
+
+            # Get test count before finishing
+            summary = self.service.get_workspace_summary()
+            test_count = summary.get('test_count', 0)
+
+            WorkspaceView.show_finish_success(issue_number, test_count)
+
+        except TddaiError as e:
+            OutputFormatter.exit_with_error(str(e))
+
+    def add_test_guidance(self) -> None:
+        """Show guidance for adding tests."""
+        try:
+            summary = self.service.get_workspace_summary()
+            if not summary['active']:
+                OutputFormatter.error("No active issue workspace")
+                print("   Run 'make tdd-start NUM=X' first")
+                OutputFormatter.exit_with_error("", 1)
+
+            issue_num = summary['issue_number']
+            issue_title = summary['issue_title']
+            workspace_dir = summary['workspace_dir']
+
+            print(f"🧪 Adding test to issue #{issue_num} workspace")
+            OutputFormatter.empty_line()
+            OutputFormatter.key_value("Issue", f"#{issue_num}: {issue_title}")
+            OutputFormatter.key_value("Workspace", f"{workspace_dir}/issue_{issue_num}/")
+            OutputFormatter.empty_line()
+
+            print("🤖 Please ask Claude Code to generate a test:")
+            OutputFormatter.empty_line()
+            print("   Command: 'Generate a test for the current workspace issue'")
+            OutputFormatter.empty_line()
+
+            print("📝 Test Requirements:")
+            print(f"   - Save test in: {workspace_dir}/issue_{issue_num}/tests/")
+            print(f"   - Name format: test_issue_{issue_num}_<scenario>.py")
+            print(f"   - Include docstring referencing issue #{issue_num}")
+            print("   - Follow TDD principles (test should fail initially)")
+            print("   - Review requirements.md and test_plan.md for context")
+            OutputFormatter.empty_line()
+
+            print("📋 Issue Details:")
+            OutputFormatter.key_value("Title", issue_title)
+            # Note: Could fetch full issue details if needed
+            OutputFormatter.empty_line()
+            print("💡 After generation: Use 'make tdd-status' to see all tests")
+
+        except TddaiError as e:
+            OutputFormatter.exit_with_error(str(e))