feat: add worktree support and refactor do skill to Python

- Add worktree module for git worktree management
- Refactor do skill scripts from shell to Python for better maintainability
- Add install.py for do skill installation
- Update stop-hook to Python implementation
- Enhance executor with additional configuration options
- Update CLAUDE.md with first-principles thinking guidelines

Generated with SWE-Agent.ai

Co-Authored-By: SWE-Agent.ai <noreply@swe-agent.ai>

codeagent-wrapper/internal/worktree/worktree.go

@@ -0,0 +1,97 @@
+package worktree
+
+import (
+	"crypto/rand"
+	"encoding/hex"
+	"fmt"
+	"io"
+	"os/exec"
+	"path/filepath"
+	"strings"
+	"time"
+)
+
+// Paths contains worktree information
+type Paths struct {
+	Dir    string // .worktrees/do-{task_id}/
+	Branch string // do/{task_id}
+	TaskID string // auto-generated task_id
+}
+
+// Hook points for testing
+var (
+	randReader  io.Reader = rand.Reader
+	timeNowFunc           = time.Now
+	execCommand           = exec.Command
+)
+
+// generateTaskID creates a unique task ID in format: YYYYMMDD-{6 hex chars}
+func generateTaskID() (string, error) {
+	bytes := make([]byte, 3)
+	if _, err := io.ReadFull(randReader, bytes); err != nil {
+		return "", fmt.Errorf("failed to generate random bytes: %w", err)
+	}
+	date := timeNowFunc().Format("20060102")
+	return fmt.Sprintf("%s-%s", date, hex.EncodeToString(bytes)), nil
+}
+
+// isGitRepo checks if the given directory is inside a git repository
+func isGitRepo(dir string) bool {
+	cmd := execCommand("git", "-C", dir, "rev-parse", "--is-inside-work-tree")
+	output, err := cmd.Output()
+	if err != nil {
+		return false
+	}
+	return strings.TrimSpace(string(output)) == "true"
+}
+
+// getGitRoot returns the root directory of the git repository
+func getGitRoot(dir string) (string, error) {
+	cmd := execCommand("git", "-C", dir, "rev-parse", "--show-toplevel")
+	output, err := cmd.Output()
+	if err != nil {
+		return "", fmt.Errorf("failed to get git root: %w", err)
+	}
+	return strings.TrimSpace(string(output)), nil
+}
+
+// CreateWorktree creates a new git worktree with auto-generated task_id
+// Returns Paths containing the worktree directory, branch name, and task_id
+func CreateWorktree(projectDir string) (*Paths, error) {
+	if projectDir == "" {
+		projectDir = "."
+	}
+
+	// Verify it's a git repository
+	if !isGitRepo(projectDir) {
+		return nil, fmt.Errorf("not a git repository: %s", projectDir)
+	}
+
+	// Get git root for consistent path calculation
+	gitRoot, err := getGitRoot(projectDir)
+	if err != nil {
+		return nil, err
+	}
+
+	// Generate task ID
+	taskID, err := generateTaskID()
+	if err != nil {
+		return nil, err
+	}
+
+	// Calculate paths
+	worktreeDir := filepath.Join(gitRoot, ".worktrees", fmt.Sprintf("do-%s", taskID))
+	branchName := fmt.Sprintf("do/%s", taskID)
+
+	// Create worktree with new branch
+	cmd := execCommand("git", "-C", gitRoot, "worktree", "add", "-b", branchName, worktreeDir)
+	if output, err := cmd.CombinedOutput(); err != nil {
+		return nil, fmt.Errorf("failed to create worktree: %w\noutput: %s", err, string(output))
+	}
+
+	return &Paths{
+		Dir:    worktreeDir,
+		Branch: branchName,
+		TaskID: taskID,
+	}, nil
+}