fix(saas): SQL type cast fixes for E2E relay flow

- key_pool.rs: cast cooldown_until to timestamptz for comparison with NOW()
- key_pool.rs: cast request_count to bigint (INT4→INT8) for sqlx decoding
- service.rs: cast cooldown_until to timestamptz in quota sort query
- scheduler.rs: cast last_seen_at to timestamptz in device cleanup
- totp.rs: use DateTime<Utc> instead of rfc3339 string for updated_at

crates/zclaw-saas/src/auth/totp.rs

@@ -226,7 +226,7 @@ pub async fn verify_totp(
         encrypt_totp_secret(&secret, &enc_key)?
     };
 
-    let now_ts = chrono::Utc::now().to_rfc3339();
+    let now_ts = chrono::Utc::now();
     sqlx::query("UPDATE accounts SET totp_enabled = true, totp_secret = $1, updated_at = $2 WHERE id = $3")
         .bind(&final_secret)
         .bind(&now_ts)
@@ -260,7 +260,7 @@ pub async fn disable_totp(
     }
 
     // 清除 TOTP
-    let now = chrono::Utc::now().to_rfc3339();
+    let now = chrono::Utc::now();
     sqlx::query("UPDATE accounts SET totp_enabled = false, totp_secret = NULL, updated_at = $1 WHERE id = $2")
         .bind(&now)
         .bind(&ctx.account_id)

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

@@ -45,11 +45,11 @@ pub async fn select_best_key(db: &PgPool, provider_id: &str, enc_key: &[u8; 32])
     let rows: Vec<(String, String, i32, Option<i64>, Option<i64>, Option<i64>, Option<i64>)> =
         sqlx::query_as(
             "SELECT pk.id, pk.key_value, pk.priority, pk.max_rpm, pk.max_tpm,
-                    uw.request_count, uw.token_count
+                    uw.request_count::bigint, 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)
+               AND (pk.cooldown_until IS NULL OR pk.cooldown_until::timestamptz <= $3)
              ORDER BY pk.priority ASC, pk.last_used_at ASC NULLS FIRST"
         ).bind(&current_minute).bind(provider_id).bind(&now).fetch_all(db).await?;
 
@@ -95,7 +95,7 @@ pub async fn select_best_key(db: &PgPool, provider_id: &str, enc_key: &[u8; 32])
         // 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(
             "SELECT cooldown_until::TEXT FROM provider_keys
-             WHERE provider_id = $1 AND is_active = TRUE AND cooldown_until IS NOT NULL AND cooldown_until > $2
+             WHERE provider_id = $1 AND is_active = TRUE AND cooldown_until IS NOT NULL AND cooldown_until::timestamptz > $2
              ORDER BY cooldown_until ASC
              LIMIT 1"
         ).bind(provider_id).bind(&now).fetch_optional(db).await?;

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

@@ -653,7 +653,7 @@ pub async fn sort_candidates_by_quota(
                 AND uw.window_minute = to_char(date_trunc('minute', NOW()), 'YYYY-MM-DDTHH24:MI')
             WHERE pk.provider_id = ANY($1)
               AND pk.is_active = TRUE
-              AND (pk.cooldown_until IS NULL OR pk.cooldown_until <= NOW())
+              AND (pk.cooldown_until IS NULL OR pk.cooldown_until::timestamptz <= NOW())
             GROUP BY pk.provider_id
             "#,
         )

crates/zclaw-saas/src/scheduler.rs

@@ -89,7 +89,7 @@ pub fn start_db_cleanup_tasks(db: PgPool) {
         loop {
             interval.tick().await;
             match sqlx::query(
-                "DELETE FROM devices WHERE last_seen_at < $1"
+                "DELETE FROM devices WHERE last_seen_at::timestamptz < $1"
             )
             .bind({
                 let cutoff = (chrono::Utc::now() - chrono::Duration::days(90));