feat: Replace external storage with local file storage + auto cleanup

Media is now stored directly on the server disk (no external service).
Files are served via Express static middleware at /uploads/*.

Cleanup rules:
- Videos deleted immediately after successful publish to Facebook/Instagram
- Videos older than 7 days purged daily by cron job
- Images older than 30 days purged daily by cron job

Changes:
- server/services/minio.ts: replaced S3 client with local fs read/write
- server/index.ts: added static serving for /uploads/media, /logos, /stories
- server/services/media-purge.ts: new rules (images 30d, videos 7d)
- server/services/scheduler.ts: delete local videos after successful publish
- docker-compose.yml: add media_uploads, logos_uploads, stories_uploads volumes
- settings UI: removed credentials card, shows local storage info
- package.json: removed googleapis (unneeded)

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

server/services/scheduler.ts

@@ -1,6 +1,7 @@
 import cron, { ScheduledTask } from "node-cron";
 import { storage } from "../storage";
 import { facebookService } from "./facebook";
+import { minioService as storageService } from "./minio";
 
 export class SchedulerService {
   private task: ScheduledTask | null = null;
@@ -124,6 +125,18 @@ export class SchedulerService {
       status: "published",
     });
 
+    // Delete local video files immediately after successful publishing
+    for (const mediaItem of mediaList) {
+      if (mediaItem.type === 'video' && mediaItem.cloudinaryPublicId) {
+        try {
+          await storageService.deleteMedia(mediaItem.cloudinaryPublicId, mediaItem.userId, 'video');
+          console.log(`[Scheduler] Deleted local video file for media ${mediaItem.id}`);
+        } catch (err) {
+          console.warn(`[Scheduler] Failed to delete local video file for media ${mediaItem.id}:`, err);
+        }
+      }
+    }
+
     console.log(`Successfully published post ${post.id} with external ID: ${externalPostId}`);
   }
 }