Restructure ORA editor into modular blueprints with browse dialog

- Split app.py into route blueprints (files, layers, images, polygon, mask, krita)
- Create services layer (polygon_storage, comfyui, file_browser)
- Extract config constants to config.py
- Split templates into Jinja partials (base, components, modals)
- Add browse dialog for visual file navigation
- Add /api/browse endpoint for directory listing

tools/ora_editor/services/file_browser.py

@@ -0,0 +1,75 @@
+"""File browsing service for project directory navigation."""
+
+import os
+from pathlib import Path
+from typing import Any
+
+
+class FileBrowserService:
+    """Service for browsing project files and directories."""
+    
+    SUPPORTED_EXTENSIONS = {'.png', '.ora'}
+    
+    def __init__(self, project_root: Path):
+        self.project_root = project_root
+    
+    def list_directory(self, relative_path: str = "") -> dict[str, Any]:
+        """List contents of a directory relative to project root."""
+        if relative_path:
+            dir_path = self.project_root / relative_path
+        else:
+            dir_path = self.project_root
+        
+        if not dir_path.exists() or not dir_path.is_dir():
+            return {
+                'success': False,
+                'error': f'Directory not found: {relative_path}'
+            }
+        
+        directories = []
+        files = []
+        
+        try:
+            for entry in sorted(dir_path.iterdir(), key=lambda e: (not e.is_dir(), e.name.lower())):
+                if entry.name.startswith('.'):
+                    continue
+                
+                if entry.is_dir():
+                    rel_path = str(entry.relative_to(self.project_root))
+                    directories.append({
+                        'name': entry.name,
+                        'path': rel_path
+                    })
+                elif entry.is_file():
+                    suffix = entry.suffix.lower()
+                    if suffix in self.SUPPORTED_EXTENSIONS:
+                        rel_path = str(entry.relative_to(self.project_root))
+                        files.append({
+                            'name': entry.name,
+                            'path': rel_path,
+                            'type': suffix[1:]
+                        })
+            
+            parent_path = None
+            if relative_path:
+                parent = Path(relative_path).parent
+                parent_path = str(parent) if parent != Path('.') else ""
+            
+            return {
+                'success': True,
+                'current_path': relative_path,
+                'parent_path': parent_path,
+                'directories': directories,
+                'files': files
+            }
+            
+        except PermissionError:
+            return {
+                'success': False,
+                'error': f'Permission denied: {relative_path}'
+            }
+        except Exception as e:
+            return {
+                'success': False,
+                'error': str(e)
+            }