fix: Persian duplicate-value errors; admin panel favicon uses the project logo

- PrismaExceptionFilter returned "Unique constraint failed on: mobile" in
  English for a duplicate. It now answers in Persian, naming the field
  (mobile, national code, member code, order number), with a safe generic
  fallback. Covered by a unit test.
- The admin panel still shipped the old "NZ" favicon. favicon.png/.ico are now
  generated from the project logo (the same one the user apps use), in both
  public/ and dist/, and the links carry ?v=2 so browsers drop the cached icon.
- Rebuilt apps/api/release/app.js.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

apps/admin-panel/index.html

@@ -3,7 +3,8 @@
   <head>
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
-    <link rel="icon" type="image/png" href="/favicon.png" />
+    <link rel="icon" type="image/png" href="/favicon.png?v=2" />
+    <link rel="shortcut icon" href="/favicon.ico?v=2" />
     <title>%BRAND_TITLE%</title>
   </head>
   <body>