Auth: nedokoncena registracia sa da dokoncit novym QR kodom

Ucet bez potvrdeneho kodu (auth_token is NULL a totp_last_step == 0)
uz neblokuje meno: opakovany register_account vyda novy secret (stary
QR prestane platit) a login vyhodi RegistrationIncomplete, na ktoru
server odpovie novym QR -- klient sa prepne na registracny tab.
Admin statistiky vykazuju nedokoncene registracie osobitne, Hraci
celkom pocita len potvrdene ucty. Novy event register v analytike.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

api/__init__.py

@@ -14,7 +14,7 @@ from bridzik import Bridzik, BridzikException, Card
 from db.db import init_db
 from api import auth as auth_module, history
 from api import stats as stats_module
-from api.auth import AuthError
+from api.auth import AuthError, RegistrationIncomplete
 
 
 def _env_bool(name: str, default: bool) -> bool:
@@ -415,6 +415,15 @@ async def confirm_account(sid, username, code):
 async def login(sid, username, code):
     try:
         identity = await auth_module.login(username, code)
+    except RegistrationIncomplete as exc:
+        # Nedokoncena registracia -> vydame novy QR kod, klient sa prepne
+        # na registracny tab a pouzivatel ju moze dokoncit.
+        try:
+            data = await auth_module.register_account(username)
+        except AuthError as exc2:
+            return await send_error(sid, str(exc2))
+        await sio.emit("register_account", data, to=sid)
+        return await send_error(sid, str(exc))
     except AuthError as exc:
         return await send_error(sid, str(exc))
     accounts[sid] = {"player_id": identity["player_id"], "username": identity["username"]}