Use short ladill.com/q links for transfer shares and emails.

Share URLs and API public_url values again use the platform domain so
ladill.com/q/* forwards to transfer.ladill.com like other Ladill apps.

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

app/Models/QrCode.php

@@ -86,14 +86,6 @@ class QrCode extends Model
         return self::publicBaseUrl() . '/q/' . $this->short_code;
     }
 
-    /** Direct link for emails and share UI — always on the Transfer app host. */
-    public function shareUrl(): string
-    {
-        $base = rtrim((string) config('app.url'), '/');
-
-        return $base . '/q/' . $this->short_code;
-    }
-
     /**
      * Base URL for public QR links. Always the short platform domain
      * (ladill.com) — never the signed-in account/product host — so printed