feat: 操作日志共享配方统一显示，移除用户删除撤销

share_recipe/adopt_recipe 统一显示为"共享配方"。
删除用户不可撤销，回退软删除方案。

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

backend/main.py

@@ -800,7 +800,9 @@ def create_recipe(recipe: RecipeIn, user=Depends(get_current_user)):
     for tag in recipe.tags:
         c.execute("INSERT OR IGNORE INTO tags (name) VALUES (?)", (tag,))
         c.execute("INSERT OR IGNORE INTO recipe_tags (recipe_id, tag_name) VALUES (?, ?)", (rid, tag))
-    log_audit(conn, user["id"], "create_recipe", "recipe", rid, recipe.name)
+    # Only log for admin/senior_editor direct adds (share); others wait for adopt
+    if user["role"] in ("admin", "senior_editor"):
+        log_audit(conn, user["id"], "share_recipe", "recipe", rid, recipe.name)
     who = user.get("display_name") or user["username"]
     if user["role"] == "senior_editor":
         # Senior editor adds directly — just inform admin