Allow deleting projects from the project picker with x/X.

Co-authored-by: Cursor <cursoragent@cursor.com>

internal/project/store.go

@@ -11,6 +11,7 @@ import (
 type Store interface {
 	List() ([]Project, error)
 	Ensure(id string) error
+	Delete(id string) error
 }
 
 // DirStore discovers projects as subdirectories of dataDir/projects.
@@ -63,3 +64,25 @@ func (s *DirStore) Ensure(id string) error {
 	}
 	return nil
 }
+
+// Delete removes the project directory and all of its files.
+func (s *DirStore) Delete(id string) error {
+	if id == "" {
+		return fmt.Errorf("project id is required")
+	}
+	dir := filepath.Join(s.projectsRoot(), id)
+	st, err := os.Stat(dir)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return fmt.Errorf("project %s: not found", id)
+		}
+		return fmt.Errorf("stat project %s: %w", id, err)
+	}
+	if !st.IsDir() {
+		return fmt.Errorf("project %s: not a directory", id)
+	}
+	if err := os.RemoveAll(dir); err != nil {
+		return fmt.Errorf("delete project %s: %w", id, err)
+	}
+	return nil
+}