feat: photo upload at level 3 + report a player (nudity avatar / chat insult)

Photo upload:
- Lower the custom profile-photo gate from level 25 to level 3 (client const +
  i18n hint + server gate in ProfileService.Update). The level-25 "Expert" title
  is unrelated and unchanged.

Report a player:
- New ReportReason type + service.reportUser(targetId, reason, details?).
- Report entry points: a "گزارش تخلف" button + reason picker (nudity / insult /
  other) in the public-profile modal, and a flag button in the chat header
  (reports the peer for an insulting chat) with a confirmation toast.
- Mock records reports to localStorage; SignalR POSTs /api/report.
- Server: POST /api/report → ProfileService.ReportUser stores the report in the
  write-only ledger (kind="report", ref="{targetId}|{reason}|{details}") so no
  schema change is needed (server uses EnsureCreated, not migrations).
- i18n: report.* keys (fa + en).

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

src/components/screens/ProfileScreen.tsx

@@ -28,7 +28,7 @@ import { pushNotification } from "@/lib/notification-store";
 import { sound } from "@/lib/sound";
 
 /** Level required before a player can upload a custom profile photo. */
-const PHOTO_UPLOAD_MIN_LEVEL = 25;
+const PHOTO_UPLOAD_MIN_LEVEL = 3;
 import { AVATARS, Gender, SocialVisibility } from "@/lib/online/types";
 import { GENDER_META, SOCIAL_PLATFORMS } from "@/lib/social";
 import { backVisualFromDef, cardBackMotif } from "@/lib/cardBack";