feat: auto-install pre-commit in session start hook

Update the SessionStart hook to automatically install pre-commit using
pip if it's not already available, rather than just showing an error
message. This ensures pre-commit is always available when starting a
Claude Code session.

Author: claude

.claude/hooks/SessionStart.sh

@@ -1,12 +1,29 @@
 #!/bin/bash
 
 # Session start hook to ensure pre-commit is installed
-echo "Installing pre-commit hooks..."
+echo "Setting up pre-commit..."
 
-# Check if pre-commit is available
+# Check if pre-commit is available, install if not
 if ! command -v pre-commit &> /dev/null; then
-    echo "Error: pre-commit is not installed. Please install it with: pip install pre-commit"
-    exit 1
+    echo "pre-commit is not installed. Installing pre-commit..."
+
+    # Try to install pre-commit using pip
+    if command -v pip3 &> /dev/null; then
+        pip3 install pre-commit
+    elif command -v pip &> /dev/null; then
+        pip install pre-commit
+    else
+        echo "Error: pip is not installed. Cannot install pre-commit."
+        exit 1
+    fi
+
+    # Verify installation
+    if ! command -v pre-commit &> /dev/null; then
+        echo "Error: Failed to install pre-commit."
+        exit 1
+    fi
+
+    echo "pre-commit installed successfully!"
 fi
 
 # Install pre-commit hooks