Fix recurrence_rule validation + smoother Sheet animation

- Add field_validator to coerce recurrence_rule from legacy strings,
  empty strings, and JSON strings into RecurrenceRule or None
- Increase Sheet slide-in duration to 350ms with cubic-bezier(0.16, 1, 0.3, 1)
  for a more premium feel

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/app/schemas/calendar_event.py

@@ -1,4 +1,6 @@
-from pydantic import BaseModel, ConfigDict
+import json as _json
+
+from pydantic import BaseModel, ConfigDict, field_validator
 from datetime import datetime
 from typing import Literal, Optional
 
@@ -16,6 +18,26 @@ class RecurrenceRule(BaseModel):
     day: Optional[int] = None      # 1-31
 
 
+def _coerce_recurrence_rule(v):
+    """Accept None, dict, RecurrenceRule, or JSON/legacy strings gracefully."""
+    if v is None or v == "" or v == "null":
+        return None
+    if isinstance(v, dict):
+        return v
+    if isinstance(v, RecurrenceRule):
+        return v
+    if isinstance(v, str):
+        try:
+            parsed = _json.loads(v)
+            if isinstance(parsed, dict):
+                return parsed
+        except (_json.JSONDecodeError, TypeError):
+            pass
+        # Legacy simple strings like "daily", "weekly" — discard (not structured)
+        return None
+    return v
+
+
 class CalendarEventCreate(BaseModel):
     title: str
     description: Optional[str] = None
@@ -24,10 +46,15 @@ class CalendarEventCreate(BaseModel):
     all_day: bool = False
     color: Optional[str] = None
     location_id: Optional[int] = None
-    recurrence_rule: Optional[RecurrenceRule] = None  # structured; router serializes to JSON string
+    recurrence_rule: Optional[RecurrenceRule] = None
     is_starred: bool = False
     calendar_id: Optional[int] = None  # If None, server assigns default calendar
 
+    @field_validator("recurrence_rule", mode="before")
+    @classmethod
+    def coerce_recurrence(cls, v):
+        return _coerce_recurrence_rule(v)
+
 
 class CalendarEventUpdate(BaseModel):
     title: Optional[str] = None
@@ -37,12 +64,17 @@ class CalendarEventUpdate(BaseModel):
     all_day: Optional[bool] = None
     color: Optional[str] = None
     location_id: Optional[int] = None
-    recurrence_rule: Optional[RecurrenceRule] = None  # structured; router serializes to JSON string
+    recurrence_rule: Optional[RecurrenceRule] = None
     is_starred: Optional[bool] = None
     calendar_id: Optional[int] = None
     # Controls which occurrences an edit applies to; absent = non-recurring or whole-series
     edit_scope: Optional[Literal["this", "this_and_future"]] = None
 
+    @field_validator("recurrence_rule", mode="before")
+    @classmethod
+    def coerce_recurrence(cls, v):
+        return _coerce_recurrence_rule(v)
+
 
 class CalendarEventResponse(BaseModel):
     id: int

frontend/src/components/ui/sheet.tsx

@@ -22,7 +22,7 @@ const Sheet: React.FC<SheetProps> = ({ open, onOpenChange, children }) => {
       document.body.style.overflow = 'hidden';
     } else {
       setVisible(false);
-      const timer = setTimeout(() => setMounted(false), 250);
+      const timer = setTimeout(() => setMounted(false), 350);
       document.body.style.overflow = '';
       return () => clearTimeout(timer);
     }
@@ -44,16 +44,17 @@ const Sheet: React.FC<SheetProps> = ({ open, onOpenChange, children }) => {
     <div className="fixed inset-0 z-50">
       <div
         className={cn(
-          'fixed inset-0 bg-background/80 backdrop-blur-sm transition-opacity duration-250',
+          'fixed inset-0 bg-background/80 backdrop-blur-sm transition-opacity duration-350 ease-out',
           visible ? 'opacity-100' : 'opacity-0'
         )}
         onClick={() => onOpenChange(false)}
       />
       <div
         className={cn(
-          'fixed right-0 top-0 h-full w-full max-w-[540px] transition-transform duration-250 ease-out',
+          'fixed right-0 top-0 h-full w-full max-w-[540px] transition-transform duration-350',
           visible ? 'translate-x-0' : 'translate-x-full'
         )}
+        style={{ transitionTimingFunction: 'cubic-bezier(0.16, 1, 0.3, 1)' }}
       >
         {children}
       </div>