feat(auth): add session management UI, QR login page, mobile QR support, translations

Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>

app/views/qr_login.py

@@ -0,0 +1,26 @@
+"""View route for the QR code mobile login page.
+
+Route:
+  GET /qr-login  — renders the QR login page (requires login)
+"""
+
+from __future__ import annotations
+
+import logging
+
+from fastapi import Request
+
+from app.views.base import APIRouter, require_login, templates
+
+logger = logging.getLogger(__name__)
+router = APIRouter()
+
+
+@router.get("/qr-login", include_in_schema=False)
+@require_login
+async def qr_login_page(request: Request):
+    """Serve the QR code login page for mobile app authentication."""
+    return templates.TemplateResponse(
+        "qr_login.html",
+        {"request": request},
+    )