feat: Engine+Schema fuer Szenario-Ende und szenario-eigene Einmalzahlungen

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

finance/app/engine/scenario.py

@@ -34,6 +34,7 @@ class PlainModifier:
     target_id: int
     kind: str
     value: Decimal
+    end_date: date | None = None
 
 
 def _modified(amount: Decimal, category_id: int | None, recurring_id: int | None,
@@ -55,6 +56,19 @@ def _modified(amount: Decimal, category_id: int | None, recurring_id: int | None
     return amount
 
 
+def _effective_end(r: PlainRecurring, modifiers: list[PlainModifier]) -> date | None:
+    """Fruehestes Ende aus eigenem end_date und allen treffenden ende-Modifikatoren."""
+    end = r.end_date
+    for m in modifiers:
+        if m.kind != "ende" or m.end_date is None:
+            continue
+        hit = ((m.target_type == "category" and r.category_id == m.target_id)
+               or (m.target_type == "recurring" and r.id == m.target_id))
+        if hit:
+            end = m.end_date if end is None else min(end, m.end_date)
+    return end
+
+
 def build_cashflows(recurring: list[PlainRecurring], planned: list[PlainPlanned],
                     loan_schedules: list[list[Installment]],
                     loan_payouts: list[tuple[date, Decimal]],
@@ -66,7 +80,7 @@ def build_cashflows(recurring: list[PlainRecurring], planned: list[PlainPlanned]
         if amount is None:
             continue
         for d in occurrences(r.rhythm, r.due_day, window_start, window_end,
-                             r.start_date, r.end_date):
+                             r.start_date, _effective_end(r, modifiers)):
             flows.append((d, amount))
     for p in planned:
         amount = _modified(p.amount, p.category_id, None, modifiers)

finance/app/models/tables.py

@@ -123,6 +123,21 @@ class ScenarioModifier(Base):
     target_id: Mapped[int] = mapped_column(Integer)
     kind: Mapped[str] = mapped_column(String(20))
     value: Mapped[Decimal] = mapped_column(MONEY, default=Decimal("0"))
+    # Nur fuer kind="ende" gesetzt: Datum, an dem der Ziel-Posten innerhalb
+    # dieses Szenarios endet (Ausbaustufe 5).
+    end_date: Mapped[date | None] = mapped_column(Date, nullable=True)
+
+
+class ScenarioPlannedItem(Base):
+    """Einmalzahlung, die NUR in einem bestimmten Szenario zaehlt -
+    unabhaengig von Scenario.include_planned (das steuert nur die globalen
+    PlannedItems). Ausbaustufe 5."""
+    __tablename__ = "scenario_planned_items"
+    id: Mapped[int] = mapped_column(primary_key=True)
+    scenario_id: Mapped[int] = mapped_column(ForeignKey("scenarios.id"), index=True)
+    name: Mapped[str] = mapped_column(String(200))
+    amount: Mapped[Decimal] = mapped_column(MONEY)
+    due: Mapped[date] = mapped_column(Date)
 
 
 class ProjectionPoint(Base):