fix: test-email actually sends; vote page pre-checks existing votes; lowercase MealPlanItemStatus everywhere

- /api/admin/test-email now calls get_email_backend().send() instead of only logging.
- /api/meals/vote/{id} GET now queries MealPlanVote and renders 'already voted' confirmation if found.
- api/meals.py: fix remaining uppercase MealPlanItemStatus enum ref (DENIED, APPROVED, PENDING).
- Fixes the 'all meals show as pending' status regression and the 'Error: Already voted' bug.

backend/app/models/__init__.py

@@ -33,11 +33,11 @@ class MealPlanStatus(enum.Enum):
     LOCKED = "locked"
 
 
-class MealPlanItemStatus(enum.Enum):
-    PENDING = "pending"
-    APPROVED = "approved"
-    DENIED = "denied"
-    SWAPPED = "swapped"
+class MealPlanItemStatus(str, enum.Enum):
+    pending = "pending"
+    approved = "approved"
+    denied = "denied"
+    swapped = "swapped"
 
 
 class ApprovalTokenStatus(enum.Enum):
@@ -221,7 +221,7 @@ class MealPlanItem(Base):
     recipe_id = Column(UUID(as_uuid=True), ForeignKey("recipe.id"))
     day_of_week = Column(Integer, nullable=False)
     meal_type = Column(SQLEnum(MealType, name="meal_type_enum", create_type=False, values_callable=lambda obj: [e.value for e in obj]), nullable=False)
-    approval_status = Column(SQLEnum(MealPlanItemStatus, name="meal_plan_item_status_enum", create_type=False, values_callable=lambda obj: [e.value for e in obj]), default=MealPlanItemStatus.PENDING)
+    approval_status = Column(SQLEnum(MealPlanItemStatus, name="meal_plan_item_status_enum", create_type=False, values_callable=lambda obj: [e.value for e in obj]), default=MealPlanItemStatus.pending)
     denial_reason = Column(SQLEnum(DenialReason, name="denial_reason_enum", create_type=False, values_callable=lambda obj: [e.value for e in obj]))
     denial_details = Column(Text)
     estimated_cost = Column(Numeric(10, 2))