feat: 配方volume字段存储编辑器选择的容量

- 后端: recipes表新增volume列，API返回/保存volume
- 前端: 保存时发送formVolume，编辑时优先用stored volume
- 容量显示优先级: stored volume > 椰子油计算 > 产品ml求和
- 修复编辑器容量选择保存后不生效的bug

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

backend/main.py

@@ -110,6 +110,7 @@ class RecipeUpdate(BaseModel):
     ingredients: Optional[list[IngredientIn]] = None
     tags: Optional[list[str]] = None
     version: Optional[int] = None
+    volume: Optional[str] = None
 
 
 class UserIn(BaseModel):
@@ -319,7 +320,7 @@ def symptom_search(body: dict, user=Depends(get_current_user)):
     conn = get_db()
     # Search in recipe names
     rows = conn.execute(
-        "SELECT id, name, note, owner_id, version, en_name FROM recipes ORDER BY id"
+        "SELECT id, name, note, owner_id, version, en_name, volume FROM recipes ORDER BY id"
     ).fetchall()
     exact = []
     related = []
@@ -773,6 +774,7 @@ def _recipe_to_dict(conn, row):
         "version": row["version"] if "version" in row.keys() else 1,
         "ingredients": [{"oil_name": i["oil_name"], "drops": i["drops"]} for i in ings],
         "tags": [t["tag_name"] for t in tags],
+        "volume": row["volume"] if "volume" in row.keys() else "",
     }
 
 
@@ -781,19 +783,19 @@ def list_recipes(user=Depends(get_current_user)):
     conn = get_db()
     # Admin sees all; others see admin-owned (adopted) + their own
     if user["role"] == "admin":
-        rows = conn.execute("SELECT id, name, note, owner_id, version, en_name FROM recipes ORDER BY id").fetchall()
+        rows = conn.execute("SELECT id, name, note, owner_id, version, en_name, volume FROM recipes ORDER BY id").fetchall()
     else:
         admin = conn.execute("SELECT id FROM users WHERE role = 'admin' LIMIT 1").fetchone()
         admin_id = admin["id"] if admin else 1
         user_id = user.get("id")
         if user_id:
             rows = conn.execute(
-                "SELECT id, name, note, owner_id, version, en_name FROM recipes WHERE owner_id = ? OR owner_id = ? ORDER BY id",
+                "SELECT id, name, note, owner_id, version, en_name, volume FROM recipes WHERE owner_id = ? OR owner_id = ? ORDER BY id",
                 (admin_id, user_id)
             ).fetchall()
         else:
             rows = conn.execute(
-                "SELECT id, name, note, owner_id, version, en_name FROM recipes WHERE owner_id = ? ORDER BY id",
+                "SELECT id, name, note, owner_id, version, en_name, volume FROM recipes WHERE owner_id = ? ORDER BY id",
                 (admin_id,)
             ).fetchall()
     result = [_recipe_to_dict(conn, r) for r in rows]
@@ -804,7 +806,7 @@ def list_recipes(user=Depends(get_current_user)):
 @app.get("/api/recipes/{recipe_id}")
 def get_recipe(recipe_id: int):
     conn = get_db()
-    row = conn.execute("SELECT id, name, note, owner_id, version, en_name FROM recipes WHERE id = ?", (recipe_id,)).fetchone()
+    row = conn.execute("SELECT id, name, note, owner_id, version, en_name, volume FROM recipes WHERE id = ?", (recipe_id,)).fetchone()
     if not row:
         conn.close()
         raise HTTPException(404, "Recipe not found")
@@ -894,6 +896,8 @@ def update_recipe(recipe_id: int, update: RecipeUpdate, user=Depends(get_current
         c.execute("UPDATE recipes SET note = ? WHERE id = ?", (update.note, recipe_id))
     if update.en_name is not None:
         c.execute("UPDATE recipes SET en_name = ? WHERE id = ?", (title_case(update.en_name), recipe_id))
+    if update.volume is not None:
+        c.execute("UPDATE recipes SET volume = ? WHERE id = ?", (update.volume, recipe_id))
     if update.ingredients is not None:
         c.execute("DELETE FROM recipe_ingredients WHERE recipe_id = ?", (recipe_id,))
         for ing in update.ingredients:
@@ -933,7 +937,7 @@ def delete_recipe(recipe_id: int, user=Depends(get_current_user)):
     conn = get_db()
     row = _check_recipe_permission(conn, recipe_id, user)
     # Save full snapshot for undo
-    full = conn.execute("SELECT id, name, note, owner_id, version, en_name FROM recipes WHERE id = ?", (recipe_id,)).fetchone()
+    full = conn.execute("SELECT id, name, note, owner_id, version, en_name, volume FROM recipes WHERE id = ?", (recipe_id,)).fetchone()
     snapshot = _recipe_to_dict(conn, full)
     log_audit(conn, user["id"], "delete_recipe", "recipe", recipe_id, row["name"],
               json.dumps(snapshot, ensure_ascii=False))
@@ -1596,7 +1600,7 @@ def recipes_by_inventory(user=Depends(get_current_user)):
     if not inv:
         conn.close()
         return []
-    rows = conn.execute("SELECT id, name, note, owner_id, version, en_name FROM recipes ORDER BY id").fetchall()
+    rows = conn.execute("SELECT id, name, note, owner_id, version, en_name, volume FROM recipes ORDER BY id").fetchall()
     result = []
     for r in rows:
         recipe = _recipe_to_dict(conn, r)