Fix entry edit always failing with 'Input should be None'

Two bugs:

1. Python 3.12 name collision in schemas.py: `date: Optional[date] = None`
   caused get_type_hints() to resolve the `date` type annotation to NoneType
   (Optional[None]) because the field name shadowed the datetime.date import.
   All *Update schemas were rejecting any PUT with a valid date. Fixed by
   aliasing the import: `from datetime import date as Date`.

2. FastAPI validation errors return detail as a list of objects, not a string.
   Passing that list to new Error() produced "Error: [object Object]". Fixed
   in api.js to map the detail array to msg strings before throwing.

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

backend/schemas.py

@@ -1,4 +1,4 @@
-from datetime import date, datetime
+from datetime import date as Date, datetime
 from decimal import Decimal
 from typing import Optional
 from pydantic import BaseModel, Field
@@ -56,18 +56,18 @@ class UserOut(BaseModel):
 # ── Egg Collections ───────────────────────────────────────────────────────────
 
 class EggCollectionCreate(BaseModel):
-    date:  date
+    date:  Date
     eggs:  int  = Field(ge=0)
     notes: Optional[str] = None
 
 class EggCollectionUpdate(BaseModel):
-    date:  Optional[date] = None
+    date:  Optional[Date] = None
     eggs:  Optional[int]  = Field(default=None, ge=0)
     notes: Optional[str]  = None
 
 class EggCollectionOut(BaseModel):
     id:         int
-    date:       date
+    date:       Date
     eggs:       int
     notes:      Optional[str]
     created_at: datetime
@@ -78,18 +78,18 @@ class EggCollectionOut(BaseModel):
 # ── Flock History ─────────────────────────────────────────────────────────────
 
 class FlockHistoryCreate(BaseModel):
-    date:          date
+    date:          Date
     chicken_count: int = Field(ge=0)
     notes:         Optional[str] = None
 
 class FlockHistoryUpdate(BaseModel):
-    date:          Optional[date] = None
+    date:          Optional[Date] = None
     chicken_count: Optional[int]  = Field(default=None, ge=0)
     notes:         Optional[str]  = None
 
 class FlockHistoryOut(BaseModel):
     id:            int
-    date:          date
+    date:          Date
     chicken_count: int
     notes:         Optional[str]
     created_at:    datetime
@@ -100,20 +100,20 @@ class FlockHistoryOut(BaseModel):
 # ── Feed Purchases ────────────────────────────────────────────────────────────
 
 class FeedPurchaseCreate(BaseModel):
-    date:          date
+    date:          Date
     bags:          Decimal = Field(gt=0, decimal_places=2)
     price_per_bag: Decimal = Field(gt=0, decimal_places=2)
     notes:         Optional[str] = None
 
 class FeedPurchaseUpdate(BaseModel):
-    date:          Optional[date]    = None
+    date:          Optional[Date]    = None
     bags:          Optional[Decimal] = Field(default=None, gt=0, decimal_places=2)
     price_per_bag: Optional[Decimal] = Field(default=None, gt=0, decimal_places=2)
     notes:         Optional[str]     = None
 
 class FeedPurchaseOut(BaseModel):
     id:            int
-    date:          date
+    date:          Date
     bags:          Decimal
     price_per_bag: Decimal
     notes:         Optional[str]
@@ -125,18 +125,18 @@ class FeedPurchaseOut(BaseModel):
 # ── Other Purchases ───────────────────────────────────────────────────────────
 
 class OtherPurchaseCreate(BaseModel):
-    date:  date
+    date:  Date
     total: Decimal = Field(gt=0, decimal_places=2)
     notes: Optional[str] = None
 
 class OtherPurchaseUpdate(BaseModel):
-    date:  Optional[date]    = None
+    date:  Optional[Date]    = None
     total: Optional[Decimal] = Field(default=None, gt=0, decimal_places=2)
     notes: Optional[str]     = None
 
 class OtherPurchaseOut(BaseModel):
     id:         int
-    date:       date
+    date:       Date
     total:      Decimal
     notes:      Optional[str]
     created_at: datetime

nginx/html/js/api.js

@@ -13,7 +13,10 @@ const API = {
 
         if (!res.ok) {
             const err = await res.json().catch(() => ({ detail: res.statusText }));
-            throw new Error(err.detail || `Request failed (${res.status})`);
+            const detail = Array.isArray(err.detail)
+                ? err.detail.map(e => e.msg).join(', ')
+                : err.detail;
+            throw new Error(detail || `Request failed (${res.status})`);
         }
         if (res.status === 204) return null;   // DELETE returns No Content
         return res.json();