fix: 修正精油名称 西洋蓍草→西洋蓍草石榴籽, 元气→元气焕能

defaults.json和数据库迁移同步更新，修复居家呵护套装少匹配1-2个油的问题。

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

backend/database.py

@@ -251,6 +251,14 @@ def init_db():
     if "volume" not in cols:
         c.execute("ALTER TABLE recipes ADD COLUMN volume TEXT DEFAULT ''")
 
+    # Migration: rename oils 西洋蓍草→西洋蓍草石榴籽, 元气→元气焕能
+    _oil_renames = [("西洋蓍草", "西洋蓍草石榴籽"), ("元气", "元气焕能")]
+    for old_name, new_name in _oil_renames:
+        exists = c.execute("SELECT 1 FROM oils WHERE name = ?", (old_name,)).fetchone()
+        if exists:
+            c.execute("UPDATE oils SET name = ? WHERE name = ?", (new_name, old_name))
+            c.execute("UPDATE recipe_ingredients SET oil_name = ? WHERE oil_name = ?", (new_name, old_name))
+
     # Seed admin user if no users exist
     count = c.execute("SELECT COUNT(*) FROM users").fetchone()[0]
     if count == 0: