feat: Implement worktree initialization script functionality

This commit introduces a new feature for managing worktree initialization scripts, allowing users to configure and execute scripts upon worktree creation. Key changes include:

1. **New API Endpoints**: Added endpoints for getting, setting, and deleting init scripts.
2. **Worktree Routes**: Updated worktree routes to include init script handling.
3. **Init Script Service**: Created a service to execute the init scripts asynchronously, with support for cross-platform compatibility.
4. **UI Components**: Added UI components for displaying and editing init scripts, including a dedicated section in the settings view.
5. **Event Handling**: Implemented event handling for init script execution status, providing real-time feedback in the UI.

This enhancement improves the user experience by allowing automated setup processes for new worktrees, streamlining project workflows.

docs/worktree-init-script-example.sh

@@ -0,0 +1,26 @@
+#!/bin/bash
+# Example worktree init script for Automaker
+# Copy this content to Settings > Worktrees > Init Script
+# Or save directly as .automaker/worktree-init.sh in your project
+
+echo "=========================================="
+echo "  Worktree Init Script Starting..."
+echo "=========================================="
+echo ""
+echo "Current directory: $(pwd)"
+echo "Branch: $(git branch --show-current 2>/dev/null || echo 'unknown')"
+echo ""
+
+# Install dependencies
+echo "[1/1] Installing npm dependencies..."
+if [ -f "package.json" ]; then
+    npm install
+    echo "Dependencies installed successfully!"
+else
+    echo "No package.json found, skipping npm install"
+fi
+echo ""
+
+echo "=========================================="
+echo "  Worktree initialization complete!"
+echo "=========================================="