feat: render full map content (image, intro, markers) in PagedJS

- Fix template check 'carte' → 'map' so map subpages are served by API
- Add parseMarker() and enrich parseCarte() with static image, intro, markers
- Include map children in parseGeoformat() alongside chapters
- Resolve map block references in chapters to full carte data
- Update narrative store flattening with new carte fields
- Replace MapBlock placeholder with full carte rendering (title, image, tags, intro, markers with icons and blocks)
- Add default marker-pin.svg for markers without custom icon

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/stores/narrative.js

@@ -61,7 +61,9 @@ export const useNarrativeStore = defineStore('narrative', () => {
             template: 'carte',
             title: child.title,
             tags: child.tags,
-            text: child.text,
+            image: child.image,
+            intro: child.intro,
+            markers: child.markers,
           });
         }
       }