fix: Bug - Sending files and attachment issues

Normalize attachment MIME types from filenames, hydrate playable media and
gallery tiles from disk without redundant peer requests, reset stalled partial
downloads, and improve gallery retry/hydration UX across chat and DMs.

Co-authored-by: Cursor <cursoragent@cursor.com>

toju-app/src/app/domains/attachment/domain/logic/attachment-normalize.rules.ts

@@ -0,0 +1,17 @@
+import { isImageAttachment } from './attachment-image.rules';
+import { resolveAttachmentMime } from './attachment-mime.rules';
+import type { AttachmentMeta } from '../models/attachment.model';
+
+export function normalizeAttachmentMeta<T extends AttachmentMeta>(meta: T): T {
+  const mime = resolveAttachmentMime(meta.filename, meta.mime);
+
+  return {
+    ...meta,
+    mime,
+    isImage: isImageAttachment({
+      filename: meta.filename,
+      isImage: meta.isImage,
+      mime
+    })
+  };
+}