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/templates/modals/browse.html

@@ -0,0 +1,68 @@
+<!-- Browse modal for file selection -->
+
+<div x-show="showBrowseModal" @keydown.escape.window="closeBrowseModal()" 
+     class="fixed inset-0 z-50 flex items-center justify-center bg-black bg-opacity-75">
+    <div class="bg-gray-800 rounded-lg p-6 max-w-2xl w-full mx-4 border border-gray-600" style="max-height: 80vh; display: flex; flex-direction: column;">
+        <div class="flex items-center justify-between mb-4">
+            <h2 class="text-xl font-bold">Open File</h2>
+            <div class="text-sm text-gray-400">
+                Current: <span x-text="browsePath || '/'"></span>
+            </div>
+        </div>
+        
+        <!-- Directory listing -->
+        <div class="flex-1 overflow-auto bg-gray-700 rounded mb-4 p-2" style="min-height: 300px;">
+            <!-- Parent directory -->
+            <div 
+                x-show="browsePath"
+                @click="navigateBrowseParent()"
+                class="flex items-center gap-2 p-2 hover:bg-gray-600 rounded cursor-pointer text-gray-300"
+            >
+                <span class="text-lg">📁</span>
+                <span>..</span>
+            </div>
+            
+            <!-- Directories -->
+            <template x-for="dir in browseDirectories" :key="'dir-' + dir.path">
+                <div 
+                    @click="navigateBrowseDirectory(dir.path)"
+                    class="flex items-center gap-2 p-2 hover:bg-gray-600 rounded cursor-pointer"
+                >
+                    <span class="text-lg">📁</span>
+                    <span x-text="dir.name"></span>
+                </div>
+            </template>
+            
+            <!-- Files -->
+            <template x-for="file in browseFiles" :key="'file-' + file.path">
+                <div 
+                    @click="selectBrowseFile(file)"
+                    @dblclick="openBrowseFile(file)"
+                    class="flex items-center gap-2 p-2 hover:bg-gray-600 rounded cursor-pointer"
+                    :class="{ 'bg-blue-600': browseSelectedPath === file.path }"
+                >
+                    <span class="text-lg" x-text="file.type === 'ora' ? '📄' : '🖼️'"></span>
+                    <span x-text="file.name"></span>
+                    <span class="text-xs text-gray-400 ml-auto uppercase" x-text="file.type"></span>
+                </div>
+            </template>
+            
+            <!-- Empty state -->
+            <div x-show="browseDirectories.length === 0 && browseFiles.length === 0" class="text-gray-400 text-center py-8">
+                No PNG or ORA files in this directory
+            </div>
+        </div>
+        
+        <!-- Actions -->
+        <div class="flex gap-4 justify-end">
+            <button @click="closeBrowseModal()" class="bg-gray-600 hover:bg-gray-500 px-4 py-2 rounded transition">Cancel</button>
+            <button 
+                @click="openSelectedFile()"
+                :disabled="!browseSelectedPath"
+                class="bg-blue-600 hover:bg-blue-700 disabled:bg-gray-600 px-4 py-2 rounded transition"
+            >
+                Open Selected
+            </button>
+        </div>
+    </div>
+</div>