fix: post thumbnail from linked design artefact, not old PostAttachments

- Post.thumbnail_url now synced from linked design artefact's first attachment
- syncPostThumbnail() called on: artefact attachment upload, artefact link/unlink
- Removed old PostAttachments-based thumbMap from GET /posts and GET /campaigns/:id/posts
- Added thumbnail_url to Posts TEXT_COLUMNS
- Caption link picker filters by copy_type='caption', body by copy_type='body'

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

server/server.js

@@ -534,6 +534,7 @@ const TEXT_COLUMNS = {
     { name: 'review_version', uidt: 'Number' },
     { name: 'caption', uidt: 'LongText' },
     { name: 'stage', uidt: 'SingleLineText' },
+    { name: 'thumbnail_url', uidt: 'SingleLineText' },
   ],
   PostAttachments: [{ name: 'version_id', uidt: 'Number' }],
   BudgetRequests: [
@@ -1243,15 +1244,7 @@ app.get('/api/posts', requireAuth, async (req, res) => {
       );
     }
 
-    // Get thumbnails
-    const allAttachments = await nocodb.list('PostAttachments', {
-      where: "(mime_type,like,image/%)",
-      limit: QUERY_LIMITS.max,
-    });
-    const thumbMap = {};
-    for (const att of allAttachments) {
-      if (att.post_id && !thumbMap[att.post_id]) thumbMap[att.post_id] = att.url;
-    }
+    // Thumbnails come from post.thumbnail_url (synced from linked design artefact)
 
     // Collect unique IDs for name lookups
     const brandIds = new Set(), userIds = new Set(), campaignIds = new Set();
@@ -1284,7 +1277,7 @@ app.get('/api/posts', requireAuth, async (req, res) => {
         assigned_name: names[`user:${p.assigned_to_id}`] || null,
         campaign_name: names[`campaign:${p.campaign_id}`] || null,
         creator_user_name: names[`user:${p.created_by_user_id}`] || null,
-        thumbnail_url: thumbMap[p.Id] || null,
+        thumbnail_url: p.thumbnail_url || null,
         approvers: approverIdList.map(id => ({ id: Number(id), name: names[`user:${Number(id)}`] || null })),
       };
     }));
@@ -3032,13 +3025,7 @@ app.get('/api/campaigns/:id/posts', requireAuth, async (req, res) => {
       sort: '-CreatedAt', limit: QUERY_LIMITS.max,
     });
 
-    const allAttachments = await nocodb.list('PostAttachments', {
-      where: "(mime_type,like,image/%)", limit: QUERY_LIMITS.max,
-    });
-    const thumbMap = {};
-    for (const att of allAttachments) {
-      if (att.post_id && !thumbMap[att.post_id]) thumbMap[att.post_id] = att.url;
-    }
+    // Thumbnails come from post.thumbnail_url (synced from linked design artefact)
 
     // Collect unique IDs for name lookups
     const brandIds = new Set(), userIds = new Set(), trackIds = new Set();
@@ -3063,7 +3050,7 @@ app.get('/api/campaigns/:id/posts', requireAuth, async (req, res) => {
       assigned_name: names[`user:${p.assigned_to_id}`] || null,
       creator_user_name: names[`user:${p.created_by_user_id}`] || null,
       track_name: names[`track:${p.track_id}`] || null,
-      thumbnail_url: thumbMap[p.Id] || null,
+      thumbnail_url: p.thumbnail_url || null,
     })));
   } catch (err) {
     res.status(500).json({ error: 'Failed to load campaign posts' });
@@ -4135,11 +4122,13 @@ app.patch('/api/artefacts/:id', requireAuth, async (req, res) => {
     const postIdsToUpdate = [...new Set([oldPostId, newPostId].filter(Boolean))];
     for (const pid of postIdsToUpdate) {
       try {
-        const { getPostComposition, computeStage } = require('./post-composition');
+        const { getPostComposition, computeStage, syncPostThumbnail } = require('./post-composition');
         const composition = await getPostComposition(pid);
         if (composition) {
           await nocodb.update('Posts', pid, { stage: computeStage(composition) });
         }
+        // Sync thumbnail if design artefact was linked/unlinked
+        if (updatedArtefact?.type === 'design') syncPostThumbnail(pid).catch(() => {});
       } catch (e) { console.error('Post stage update error:', e); }
     }
 
@@ -4542,6 +4531,12 @@ app.post('/api/artefacts/:id/versions/:versionId/attachments', requireAuth, dyna
       ...attachment,
       url: attachment.drive_url || `/api/uploads/${attachment.filename}`,
     });
+
+    // Sync post thumbnail if this is a design artefact linked to a post
+    if (artefact.post_id && (artefact.type === 'design')) {
+      const { syncPostThumbnail } = require('./post-composition');
+      syncPostThumbnail(artefact.post_id).catch(() => {});
+    }
   } catch (err) {
     console.error('Upload attachment error:', err);
     res.status(500).json({ error: 'Failed to upload attachment' });