refactor: one PHP file per route with subdirectories

Properly organize routes following design-to-pack pattern:
- routes/markers/get.php
- routes/markers/create.php
- routes/markers/update.php
- routes/markers/delete.php
- routes/position/update.php
- routes/image/capture.php
- routes/image/check-flag.php
- routes/image/clear-flag.php

Each route in its own file for better maintainability.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

public/site/plugins/map-editor/routes/image/check-flag.php

@@ -0,0 +1,39 @@
+<?php
+
+/**
+ * GET check if regeneration flag exists
+ */
+
+return [
+    'pattern' => 'map-editor/pages/(:all)/check-regenerate-flag',
+    'method' => 'GET',
+    'auth' => false,
+    'action' => function (string $pageId) {
+        try {
+            $page = kirby()->page($pageId);
+            if (!$page) {
+                return [
+                    'status' => 'error',
+                    'message' => 'Page not found',
+                    'code' => 404
+                ];
+            }
+
+            $markerFile = $page->root() . '/.regenerate-map-image';
+            $needsRegeneration = file_exists($markerFile);
+
+            return [
+                'status' => 'success',
+                'data' => [
+                    'needsRegeneration' => $needsRegeneration
+                ]
+            ];
+        } catch (Exception $e) {
+            return [
+                'status' => 'error',
+                'message' => $e->getMessage(),
+                'code' => 500
+            ];
+        }
+    }
+];