fix: Szenario-Vergleich zeigt vor heute Ist-Saldo, veraltete Szenarien werden neu gerechnet (A11-T2)

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

finance/app/routers/gui.py

@@ -1,5 +1,7 @@
+import logging
 from datetime import date, timedelta
 from decimal import Decimal
+from typing import Callable
 
 from fastapi import APIRouter, Depends, HTTPException, Request
 from fastapi.templating import Jinja2Templates
@@ -25,6 +27,7 @@ from app.routers.planning import recurring_suggestions as _recurring_suggestions
 from app.routers.scenarios import list_scenarios as _list_scenarios
 from app.routers.transactions import count_transactions, list_transactions
 from app.services.balances import account_balance, total_balance
+from app.services.projection_service import refresh_stale_projections
 from app.version import get_version
 
 PAGE_SIZE = 50
@@ -51,6 +54,21 @@ templates.env.filters["eur"] = eur
 templates.env.filters["de_label"] = de_label
 router = APIRouter()
 
+log = logging.getLogger(__name__)
+
+
+def _safe_refresh(session: Session, refresh: Callable[[Session, date], object],
+                  today: date) -> None:
+    """Frischt abgeleitete Daten (Projektionen, Planungs-Diagramm) vor dem
+    Rendern auf. Ein Fehler darf die Seite nie brechen: rollback, Warnung ins
+    Log, die Seite rendert mit dem vorhandenen Stand."""
+    try:
+        refresh(session, today)
+    except Exception:
+        session.rollback()
+        log.warning("Auffrischen fehlgeschlagen: %s",
+                    getattr(refresh, "__name__", refresh), exc_info=True)
+
 
 def gui_session(request: Request):
     if not session_valid(request.cookies.get(COOKIE)):
@@ -127,6 +145,7 @@ def _month_starts_desc(session: Session, today: date) -> list[date]:
 
 @router.get("/", dependencies=[Depends(gui_session)])
 def index(request: Request, session: Session = Depends(get_session)):
+    _safe_refresh(session, refresh_stale_projections, date.today())
     accounts = session.execute(select(Account)).scalars().all()
     balances = [(a, account_balance(session, a)) for a in accounts]
     return templates.TemplateResponse(request, "index.html", {
@@ -323,6 +342,7 @@ def planung_page(request: Request, session: Session = Depends(get_session)):
 
 @router.get("/szenarien", dependencies=[Depends(gui_session)])
 def szenarien_page(request: Request, session: Session = Depends(get_session)):
+    _safe_refresh(session, refresh_stale_projections, date.today())
     categories = session.execute(select(Category)).scalars().all()
     recurring = _list_recurring(session=session)
     loans = _list_loans(session=session)