Polish: daily reward via celebration overlay + premium chat to recipient

- Daily reward now routes through the global CelebrationOverlay: new "daily"
  variant + coins count-up; claiming closes the daily modal and fires
  celebrate({variant:"daily", coins}). Unifies the "you earned X" moment.
- Premium (pro) gold chat is now visible to the OTHER player: ChatMessage gains
  senderPro; server resolves each participant's plan once (SocialService.IsPro)
  and stamps it on ChatMessageDto; ChatScreen styles incoming bubbles with
  .premium-chat when senderPro. Mock marks ~half its friends pro so it's visible
  offline too.

Verified: tsc + next build + dotnet build all pass.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/lib/online/mock-service.ts

@@ -616,11 +616,14 @@ export class MockOnlineService implements OnlineService {
       fromMe: true,
       text: text.trim(),
       ts: Date.now(),
+      senderPro: this.profile?.plan === "pro",
     };
     this.messages[friendId] = [...(this.messages[friendId] ?? []), msg];
     this.saveChats();
     this.emitChat(friendId);
 
+    // deterministic: ~half of mock friends are "pro" so the gold bubble is visible offline
+    const friendPro = [...friendId].reduce((a, c) => a + c.charCodeAt(0), 0) % 2 === 0;
     // simulate a reply from the friend
     this.after(randInt(900, 1900), () => {
       const reply: ChatMessage = {
@@ -628,6 +631,7 @@ export class MockOnlineService implements OnlineService {
         fromMe: false,
         text: pick(CANNED_REPLIES),
         ts: Date.now(),
+        senderPro: friendPro,
       };
       this.messages[friendId] = [...(this.messages[friendId] ?? []), reply];
       this.unread[friendId] = (this.unread[friendId] ?? 0) + 1;