feat: 共享配方审核完整流程

- 新增 /api/recipes/{id}/reject 端点：拒绝配方并通知提交者（含原因）
- 采纳配方时通知提交者"配方已采纳"
- 管理员拒绝配方时输入原因
- 贡献统计改为统计被采纳的配方数（含 audit_log 记录）
- 完整流程测试：共享→通知→拒绝(带原因)→通知→重新共享→采纳→通知

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

backend/main.py

@@ -863,11 +863,48 @@ def adopt_recipe(recipe_id: int, user=Depends(require_role("admin"))):
     if row["owner_id"] == user["id"]:
         conn.close()
         return {"ok": True, "msg": "already owned"}
-    old_owner = conn.execute("SELECT display_name, username FROM users WHERE id = ?", (row["owner_id"],)).fetchone()
+    old_owner = conn.execute("SELECT id, role, display_name, username FROM users WHERE id = ?", (row["owner_id"],)).fetchone()
     old_name = (old_owner["display_name"] or old_owner["username"]) if old_owner else "unknown"
     conn.execute("UPDATE recipes SET owner_id = ?, updated_by = ? WHERE id = ?", (user["id"], user["id"], recipe_id))
     log_audit(conn, user["id"], "adopt_recipe", "recipe", recipe_id, row["name"],
               json.dumps({"from_user": old_name}))
+    # Notify submitter that recipe was approved
+    if old_owner and old_owner["id"] != user["id"]:
+        conn.execute(
+            "INSERT INTO notifications (target_role, title, body, target_user_id) VALUES (?, ?, ?, ?)",
+            (old_owner["role"], "🎉 配方已采纳",
+             f"你共享的配方「{row['name']}」已被采纳到公共配方库！", old_owner["id"])
+        )
+    conn.commit()
+    conn.close()
+    return {"ok": True}
+
+
+@app.post("/api/recipes/{recipe_id}/reject")
+def reject_recipe(recipe_id: int, body: dict = None, user=Depends(require_role("admin"))):
+    conn = get_db()
+    row = conn.execute("SELECT id, name, owner_id FROM recipes WHERE id = ?", (recipe_id,)).fetchone()
+    if not row:
+        conn.close()
+        raise HTTPException(404, "Recipe not found")
+    reason = (body or {}).get("reason", "").strip()
+    # Notify submitter
+    old_owner = conn.execute("SELECT id, role, display_name, username FROM users WHERE id = ?", (row["owner_id"],)).fetchone()
+    if old_owner and old_owner["id"] != user["id"]:
+        msg = f"你共享的配方「{row['name']}」未被采纳。"
+        if reason:
+            msg += f"\n原因：{reason}"
+        msg += "\n你可以修改后重新共享。"
+        conn.execute(
+            "INSERT INTO notifications (target_role, title, body, target_user_id) VALUES (?, ?, ?, ?)",
+            (old_owner["role"], "配方未被采纳", msg, old_owner["id"])
+        )
+    # Delete the recipe
+    conn.execute("DELETE FROM recipe_ingredients WHERE recipe_id = ?", (recipe_id,))
+    conn.execute("DELETE FROM recipe_tags WHERE recipe_id = ?", (recipe_id,))
+    conn.execute("DELETE FROM recipes WHERE id = ?", (recipe_id,))
+    log_audit(conn, user["id"], "reject_recipe", "recipe", recipe_id, row["name"],
+              json.dumps({"reason": reason}))
     conn.commit()
     conn.close()
     return {"ok": True}
@@ -1407,11 +1444,17 @@ def my_contribution(user=Depends(get_current_user)):
     if not user.get("id"):
         return {"shared_count": 0}
     conn = get_db()
+    # Count recipes adopted from this user (tracked in audit_log)
     count = conn.execute(
+        "SELECT COUNT(*) FROM audit_log WHERE action = 'adopt_recipe' AND detail LIKE ?",
+        (f'%"from_user": "{user.get("display_name") or user.get("username")}"%',)
+    ).fetchone()[0]
+    # Also count recipes still owned by user in public library
+    own_count = conn.execute(
         "SELECT COUNT(*) FROM recipes WHERE owner_id = ?", (user["id"],)
     ).fetchone()[0]
     conn.close()
-    return {"shared_count": count}
+    return {"shared_count": count + own_count}
 
 
 # ── Notifications ──────────────────────────────────────