fix(gui): Simplified project selection workflow

Fixes:
- Single 'Select Project Folder' button replaces confusing New/Open
- Auto-creates project if folder is empty or has no project.json
- Auto-opens project if project.json exists
- Removed editable project name field (was confusing)
- Fixed 'directory not empty' error - now handles existing folders gracefully
- Better error messages and confirmations
- Project path shown as read-only label

The flow is now:
1. Click 'Select Project Folder'
2. Pick any folder
3. If new: project created automatically
   If existing: project opened automatically

TODO: Multilingual transcription support (Whisper handles mixed FR/EN poorly)

src/cad_documenter/gui.py

@@ -158,7 +158,6 @@ class CADDocumenterGUI:
         self.config = load_config()
         
         self._create_widgets()
-        self._update_project_list()
     
     def _create_widgets(self):
         """Create the main UI widgets."""
@@ -166,37 +165,32 @@ class CADDocumenterGUI:
         main_frame = ctk.CTkFrame(self.root) if USE_CTK else ttk.Frame(self.root)
         main_frame.pack(fill="both", expand=True, padx=10, pady=10)
         
-        # === Project Section ===
+        # === Project Section (Simplified) ===
         project_frame = ctk.CTkFrame(main_frame) if USE_CTK else ttk.LabelFrame(main_frame, text="Project")
         project_frame.pack(fill="x", pady=(0, 10))
         
         if USE_CTK:
-            ctk.CTkLabel(project_frame, text="Project:", font=("", 14, "bold")).pack(anchor="w", padx=10, pady=(10, 5))
+            ctk.CTkLabel(project_frame, text="Project Folder:", font=("", 14, "bold")).pack(anchor="w", padx=10, pady=(10, 5))
         
         proj_row = ctk.CTkFrame(project_frame) if USE_CTK else ttk.Frame(project_frame)
         proj_row.pack(fill="x", padx=10, pady=(0, 10))
         
-        self.project_var = tk.StringVar()
+        # Project path display (read-only)
-        self.project_combo = ctk.CTkComboBox(
+        self.project_path_var = tk.StringVar(value="No project selected")
-            proj_row, 
+        if USE_CTK:
-            variable=self.project_var,
+            self.project_path_label = ctk.CTkLabel(proj_row, textvariable=self.project_path_var, 
-            values=[],
+                                                    anchor="w", width=450)
-            width=400,
+        else:
-            command=self._on_project_selected
+            self.project_path_label = ttk.Label(proj_row, textvariable=self.project_path_var)
-        ) if USE_CTK else ttk.Combobox(proj_row, textvariable=self.project_var, width=50)
+        self.project_path_label.pack(side="left", fill="x", expand=True)
-        self.project_combo.pack(side="left", padx=(0, 10))
         
-        if not USE_CTK:
+        # Single "Select Project" button
-            self.project_combo.bind("<<ComboboxSelected>>", lambda e: self._on_project_selected(None))
+        btn_select = ctk.CTkButton(proj_row, text="📁 Select Project Folder", width=180, 
+                                   command=self._select_project) if USE_CTK else ttk.Button(proj_row, text="Select Folder", command=self._select_project)
+        btn_select.pack(side="right", padx=(10, 0))
         
-        btn_new = ctk.CTkButton(proj_row, text="+ New", width=80, command=self._new_project) if USE_CTK else ttk.Button(proj_row, text="+ New", command=self._new_project)
+        # Project info (read-only)
-        btn_new.pack(side="left", padx=5)
+        self.project_info_var = tk.StringVar(value="Select a folder to create or open a project")
-        
-        btn_open = ctk.CTkButton(proj_row, text="Open", width=80, command=self._open_project) if USE_CTK else ttk.Button(proj_row, text="Open", command=self._open_project)
-        btn_open.pack(side="left", padx=5)
-        
-        # Project info
-        self.project_info_var = tk.StringVar(value="No project loaded")
         if USE_CTK:
             self.project_info = ctk.CTkLabel(project_frame, textvariable=self.project_info_var, text_color="gray")
         else:
@@ -257,7 +251,7 @@ class CADDocumenterGUI:
         cb_scene.pack(anchor="w", pady=2)
         
         self.transcribe_var = tk.BooleanVar(value=True)
-        cb_trans = ctk.CTkCheckBox(opts_inner, text="Whisper transcription (local GPU)", variable=self.transcribe_var) if USE_CTK else ttk.Checkbutton(opts_inner, text="Whisper transcription", variable=self.transcribe_var)
+        cb_trans = ctk.CTkCheckBox(opts_inner, text="Whisper transcription (local GPU, auto-detect language)", variable=self.transcribe_var) if USE_CTK else ttk.Checkbutton(opts_inner, text="Whisper transcription", variable=self.transcribe_var)
         cb_trans.pack(anchor="w", pady=2)
         
         # === Process Button ===
@@ -274,7 +268,7 @@ class CADDocumenterGUI:
         status_frame = ctk.CTkFrame(main_frame) if USE_CTK else ttk.Frame(main_frame)
         status_frame.pack(fill="x")
         
-        self.status_var = tk.StringVar(value="Ready — Open or create a project to start")
+        self.status_var = tk.StringVar(value="Ready — Select a project folder to start")
         status_label = ctk.CTkLabel(status_frame, textvariable=self.status_var) if USE_CTK else ttk.Label(status_frame, textvariable=self.status_var)
         status_label.pack(side="left", padx=5)
         
@@ -287,19 +281,14 @@ class CADDocumenterGUI:
         """Get the next generation number for the current project."""
         if not self.current_project:
             return 1
-        
-        # Count existing videos as generations
         return len(self.current_project.manifest.videos) + 1
     
-    def _update_project_list(self):
-        """Update the project dropdown with recent projects."""
-        pass  # Could load from config/history
-    
     def _update_project_info(self):
         """Update the project info display."""
         if not self.current_project:
-            self.project_info_var.set("No project loaded")
+            self.project_info_var.set("Select a folder to create or open a project")
             self.next_gen_var.set("")
+            self.project_path_var.set("No project selected")
             return
         
         m = self.current_project.manifest
@@ -307,58 +296,86 @@ class CADDocumenterGUI:
         pending = len(self.current_project.get_pending_videos())
         processed = total - pending
         
-        info = f"📁 {m.name} — {total} videos ({processed} processed, {pending} pending)"
+        self.project_path_var.set(str(self.current_project.project_dir))
+        
+        if total == 0:
+            info = f"✓ Project: {m.name} — No videos yet, add one!"
+        else:
+            info = f"✓ Project: {m.name} — {total} videos ({processed} processed, {pending} pending)"
         self.project_info_var.set(info)
         
         next_gen = self._get_next_gen_number()
         self.next_gen_var.set(f"Next: Gen {next_gen:03d}")
     
-    def _on_project_selected(self, value):
+    def _select_project(self):
-        """Handle project selection."""
+        """Select a folder - creates project if empty/new, opens if existing."""
-        self._refresh_video_list()
+        folder = filedialog.askdirectory(title="Select Project Folder")
-        self._update_project_info()
-    
-    def _new_project(self):
-        """Create a new project."""
-        folder = filedialog.askdirectory(title="Select folder for new project")
         if not folder:
             return
         
-        name = Path(folder).name
+        folder_path = Path(folder)
+        project_json = folder_path / "project.json"
         
-        # Dialog for project name
+        if project_json.exists():
-        if USE_CTK:
+            # Existing project - just open it
-            dialog = ctk.CTkInputDialog(
+            try:
-                text="Enter project name:", 
+                self.current_project = Project.load(folder_path)
-                title="New Project"
+                self.status_var.set(f"✓ Opened: {self.current_project.manifest.name}")
+                self._refresh_video_list()
+                self._update_project_info()
+            except Exception as e:
+                messagebox.showerror("Error", f"Failed to load project:\n{e}")
+        else:
+            # New project - create it
+            # Use folder name as project name
+            name = folder_path.name
+            
+            # Check if folder has other files (not empty but no project.json)
+            existing_files = list(folder_path.iterdir()) if folder_path.exists() else []
+            
+            if existing_files:
+                # Folder has files but no project.json - ask to initialize here
+                if not messagebox.askyesno(
+                    "Initialize Project?",
+                    f"Folder '{name}' exists but has no project.\n\n"
+                    f"Create a new CAD Documenter project here?\n\n"
+                    f"(Existing files will not be deleted)"
+                ):
+                    return
+            
+            try:
+                # Create project (handles existing folder gracefully)
+                folder_path.mkdir(parents=True, exist_ok=True)
+                
+                # Manually create structure without the "not empty" check
+                (folder_path / "videos").mkdir(exist_ok=True)
+                (folder_path / "knowledge").mkdir(exist_ok=True)
+                (folder_path / "knowledge" / "transcripts").mkdir(exist_ok=True)
+                (folder_path / "frames").mkdir(exist_ok=True)
+                (folder_path / "output").mkdir(exist_ok=True)
+                (folder_path / "context").mkdir(exist_ok=True)
+                (folder_path / "clawdbot_export").mkdir(exist_ok=True)
+                
+                # Create manifest
+                from .project import ProjectManifest
+                now = datetime.now().isoformat()
+                manifest = ProjectManifest(
+                    name=name,
+                    created_at=now,
+                    updated_at=now,
+                    description="",
                 )
-            name = dialog.get_input() or name
                 
-        try:
+                self.current_project = Project(folder_path)
-            self.current_project = Project.create(Path(folder), name, "")
+                self.current_project.manifest = manifest
-            self.project_var.set(f"{name}")
+                self.current_project.save()
-            self.status_var.set(f"✓ Created project: {name}")
+                
+                self.status_var.set(f"✓ Created new project: {name}")
                 self._refresh_video_list()
                 self._update_project_info()
-        except Exception as e:
-            messagebox.showerror("Error", str(e))
                 
-    def _open_project(self):
-        """Open an existing project."""
-        folder = filedialog.askdirectory(title="Select project folder")
-        if not folder:
-            return
-        
-        try:
-            self.current_project = Project.load(Path(folder))
-            self.project_var.set(f"{self.current_project.manifest.name}")
-            self.status_var.set(f"✓ Loaded: {self.current_project.manifest.name}")
-            self._refresh_video_list()
-            self._update_project_info()
-        except FileNotFoundError:
-            messagebox.showerror("Error", f"No project.json found in {folder}\n\nUse '+ New' to create a new project.")
             except Exception as e:
-            messagebox.showerror("Error", f"Failed to load project: {e}")
+                messagebox.showerror("Error", f"Failed to create project:\n{e}")
     
     def _refresh_video_list(self):
         """Refresh the video listbox."""
@@ -382,7 +399,7 @@ class CADDocumenterGUI:
     def _add_videos(self):
         """Add videos to the project with topic dialog."""
         if not self.current_project:
-            messagebox.showwarning("Warning", "Please create or open a project first")
+            messagebox.showwarning("Warning", "Please select a project folder first")
             return
         
         files = filedialog.askopenfilenames(
@@ -433,7 +450,7 @@ class CADDocumenterGUI:
         if not selection:
             return
         
-        if not messagebox.askyesno("Confirm", "Remove selected video(s) from project?"):
+        if not messagebox.askyesno("Confirm", "Remove selected video(s) from project?\n\n(Video files will be deleted)"):
             return
         
         # Remove in reverse order to maintain indices
@@ -453,17 +470,17 @@ class CADDocumenterGUI:
     def _process_videos(self):
         """Process videos in background thread."""
         if not self.current_project:
-            messagebox.showwarning("Warning", "Please create or open a project first")
+            messagebox.showwarning("Warning", "Please select a project folder first")
             return
         
         pending = self.current_project.get_pending_videos()
         if not pending:
-            messagebox.showinfo("Info", "No pending videos to process")
+            messagebox.showinfo("Info", "No pending videos to process.\n\nAdd a video first!")
             return
         
         # Disable button during processing
         self.btn_process.configure(state="disabled")
-        self.status_var.set(f"Processing {len(pending)} video(s)...")
+        self.status_var.set(f"Processing {len(pending)} video(s)... (this may take a few minutes)")
         
         if USE_CTK:
             self.progress.set(0)