fix: Bug - Sending files and attachment issues (gallery load and speed)

Route small images through in-memory receive instead of serialized disk
chunk-acks, and improve gallery hydration for local copies and pending
downloads so thumbnails display without minutes-long progress stalls.

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

toju-app/src/app/domains/chat/domain/rules/chat-message-image-gallery.rules.spec.ts

@@ -4,7 +4,7 @@ import {
   it
 } from 'vitest';
 
-import { buildChatMessageGalleryTiles } from './chat-message-image-gallery.rules';
+import { buildChatMessageGalleryTiles, resolveChatMessageGalleryTileState } from './chat-message-image-gallery.rules';
 
 describe('buildChatMessageGalleryTiles', () => {
   it('marks displayable, hydrating, downloading, and retry tiles from attachment state', () => {
@@ -51,4 +51,18 @@ describe('buildChatMessageGalleryTiles', () => {
       'retry'
     ]);
   });
+
+  it('treats zero-byte pending requests as downloading instead of retry', () => {
+    const attachment = {
+      id: 'pending',
+      filename: 'waiting.png',
+      mime: 'image/png',
+      isImage: true,
+      available: false,
+      size: 256
+    };
+
+    expect(resolveChatMessageGalleryTileState(attachment)).toBe('retry');
+    expect(resolveChatMessageGalleryTileState(attachment, { pendingRequest: true })).toBe('downloading');
+  });
 });