fix(saas): P1 审计修复 — 连接池断路器 + Worker重试 + XSS防护 + 状态机SQL解析器

P1 修复内容:
- F7: health handler 连接池容量检查 (80%阈值返回503 degraded)
- F9: SSE spawned task 并发限制 (Semaphore 16 permits)
- F10: Key Pool 单次 JOIN 查询优化 (消除 N+1)
- F12: CORS panic → 配置错误
- F14: 连接池使用率计算修正 (ratio = used*100/total)
- F15: SQL 迁移解析器替换为状态机 (支持 $$, DO $body$, 存储过程)
- Worker 重试机制: 失败任务通过 mpsc channel 重新入队
- DOMPurify XSS 防护 (PipelineResultPreview)
- Admin V2: ErrorBoundary + SWR全局配置 + 请求优化

crates/zclaw-saas/src/relay/key_pool.rs

@@ -4,7 +4,7 @@
 
 use sqlx::PgPool;
 use crate::error::{SaasError, SaasResult};
-use crate::models::{ProviderKeySelectRow, ProviderKeyRow};
+ use crate::models::ProviderKeyRow;
 use crate::crypto;
 
 /// 解密 key_value (如果已加密)，否则原样返回
@@ -36,19 +36,63 @@ pub struct KeySelection {
 }
 
 /// 从 provider 的 Key Pool 中选择最佳可用 Key
+///
+/// 优化: 单次 JOIN 查询获取 Key + 当前分钟使用量，避免 N+1 查询
 pub async fn select_best_key(db: &PgPool, provider_id: &str, enc_key: &[u8; 32]) -> SaasResult<KeySelection> {
     let now = chrono::Utc::now().to_rfc3339();
     let current_minute = chrono::Utc::now().format("%Y-%m-%dT%H:%M").to_string();
 
-    // 获取所有活跃 Key
-    let rows: Vec<ProviderKeySelectRow> =
+    // 单次查询: 活跃 Key + 当前分钟的 RPM/TPM 使用量 (LEFT JOIN)
+    let rows: Vec<(String, String, i32, Option<i64>, Option<i64>, Option<String>, Option<i64>, Option<i64>)> =
         sqlx::query_as(
-            "SELECT id, key_value, priority, max_rpm, max_tpm, quota_reset_interval
-             FROM provider_keys
-             WHERE provider_id = $1 AND is_active = TRUE AND (cooldown_until IS NULL OR cooldown_until <= $2)
-             ORDER BY priority ASC"
-        ).bind(provider_id).bind(&now).fetch_all(db).await?;
+            "SELECT pk.id, pk.key_value, pk.priority, pk.max_rpm, pk.max_tpm, pk.quota_reset_interval,
+                    uw.request_count, uw.token_count
+             FROM provider_keys pk
+             LEFT JOIN key_usage_window uw ON pk.id = uw.key_id AND uw.window_minute = $1
+             WHERE pk.provider_id = $2 AND pk.is_active = TRUE
+               AND (pk.cooldown_until IS NULL OR pk.cooldown_until <= $3)
+             ORDER BY pk.priority ASC"
+        ).bind(&current_minute).bind(provider_id).bind(&now).fetch_all(db).await?;
 
+    for (id, key_value, priority, max_rpm, max_tpm, quota_reset_interval, req_count, token_count) in &rows {
+        // RPM 检查
+        if let Some(rpm_limit) = max_rpm {
+            if *rpm_limit > 0 {
+                let count = req_count.unwrap_or(0);
+                if count >= *rpm_limit {
+                    tracing::debug!("Key {} hit RPM limit ({}/{})", id, count, rpm_limit);
+                    continue;
+                }
+            }
+        }
+
+        // TPM 检查
+        if let Some(tpm_limit) = max_tpm {
+            if *tpm_limit > 0 {
+                let tokens = token_count.unwrap_or(0);
+                if tokens >= *tpm_limit {
+                    tracing::debug!("Key {} hit TPM limit ({}/{})", id, tokens, tpm_limit);
+                    continue;
+                }
+            }
+        }
+
+        // 此 Key 可用 — 解密 key_value
+        let decrypted_kv = decrypt_key_value(key_value, enc_key)?;
+        return Ok(KeySelection {
+            key: PoolKey {
+                id: id.clone(),
+                key_value: decrypted_kv,
+                priority: *priority,
+                max_rpm: *max_rpm,
+                max_tpm: *max_tpm,
+                quota_reset_interval: quota_reset_interval.clone(),
+            },
+            key_id: id.clone(),
+        });
+    }
+
+    // 所有 Key 都超限或无 Key
     if rows.is_empty() {
         // 检查是否有冷却中的 Key，返回预计等待时间
         let cooldown_row: Option<(String,)> = sqlx::query_as(
@@ -59,88 +103,14 @@ pub async fn select_best_key(db: &PgPool, provider_id: &str, enc_key: &[u8; 32])
         ).bind(provider_id).bind(&now).fetch_optional(db).await?;
 
         if let Some((earliest,)) = cooldown_row {
-            // 尝试解析时间差
             let wait_secs = parse_cooldown_remaining(&earliest, &now);
             return Err(SaasError::RateLimited(
                 format!("所有 Key 均在冷却中，预计 {} 秒后可用", wait_secs)
             ));
         }
-
-        // 检查 provider 级别的单 Key
-        let provider_key: Option<String> = sqlx::query_scalar(
-            "SELECT api_key FROM providers WHERE id = $1"
-        ).bind(provider_id).fetch_optional(db).await?.flatten();
-
-        if let Some(key) = provider_key {
-            let decrypted = decrypt_key_value(&key, enc_key)?;
-            return Ok(KeySelection {
-                key: PoolKey {
-                    id: "provider-fallback".to_string(),
-                    key_value: decrypted,
-                    priority: 0,
-                    max_rpm: None,
-                    max_tpm: None,
-                    quota_reset_interval: None,
-                },
-                key_id: "provider-fallback".to_string(),
-            });
-        }
-
-        return Err(SaasError::NotFound(format!("Provider {} 没有可用的 API Key", provider_id)));
     }
 
-    // 检查滑动窗口使用量
-    for row in rows {
-        // 检查 RPM 限额
-        if let Some(rpm_limit) = row.max_rpm {
-            if rpm_limit > 0 {
-                let window: Option<(i64,)> = sqlx::query_as(
-                    "SELECT COALESCE(SUM(request_count), 0) FROM key_usage_window
-                     WHERE key_id = $1 AND window_minute = $2"
-                ).bind(&row.id).bind(&current_minute).fetch_optional(db).await?;
-
-                if let Some((count,)) = window {
-                    if count >= rpm_limit {
-                        tracing::debug!("Key {} hit RPM limit ({}/{})", row.id, count, rpm_limit);
-                        continue;
-                    }
-                }
-            }
-        }
-
-        // 检查 TPM 限额
-        if let Some(tpm_limit) = row.max_tpm {
-            if tpm_limit > 0 {
-                let window: Option<(i64,)> = sqlx::query_as(
-                    "SELECT COALESCE(SUM(token_count), 0) FROM key_usage_window
-                     WHERE key_id = $1 AND window_minute = $2"
-                ).bind(&row.id).bind(&current_minute).fetch_optional(db).await?;
-
-                if let Some((tokens,)) = window {
-                    if tokens >= tpm_limit {
-                        tracing::debug!("Key {} hit TPM limit ({}/{})", row.id, tokens, tpm_limit);
-                        continue;
-                    }
-                }
-            }
-        }
-
-        // 此 Key 可用 — 解密 key_value
-        let decrypted_kv = decrypt_key_value(&row.key_value, enc_key)?;
-        return Ok(KeySelection {
-            key: PoolKey {
-                id: row.id.clone(),
-                key_value: decrypted_kv,
-                priority: row.priority,
-                max_rpm: row.max_rpm,
-                max_tpm: row.max_tpm,
-                quota_reset_interval: row.quota_reset_interval,
-            },
-            key_id: row.id,
-        });
-    }
-
-    // 所有 Key 都超限，回退到 provider 单 Key
+    // 回退到 provider 单 Key
     let provider_key: Option<String> = sqlx::query_scalar(
         "SELECT api_key FROM providers WHERE id = $1"
     ).bind(provider_id).fetch_optional(db).await?.flatten();
@@ -160,9 +130,13 @@ pub async fn select_best_key(db: &PgPool, provider_id: &str, enc_key: &[u8; 32])
         });
     }
 
-    Err(SaasError::RateLimited(
-        format!("Provider {} 所有 Key 均已达限额", provider_id)
-    ))
+    if rows.is_empty() {
+        Err(SaasError::NotFound(format!("Provider {} 没有可用的 API Key", provider_id)))
+    } else {
+        Err(SaasError::RateLimited(
+            format!("Provider {} 所有 Key 均已达限额", provider_id)
+        ))
+    }
 }
 
 /// 记录 Key 使用量（滑动窗口）