fix(wallet): 修复余额不足后重复消费

- 有限钱包结算允许扣成负数，先扣充值余额再扣赠送余额，缺口回写到充值余额
- 日额度钱包补扣路径在存在钱包时不再把余额不足标成 insufficient_quota
- 补充内存和 SQLite 结算回归覆盖，三种数据库实现保持一致
验证:
- cargo fmt --all --check
- cargo clippy -p aether-data --all-targets -- -D warnings
- cargo clippy -p aether-gateway --all-targets -- -D warnings
- cargo clippy --workspace --exclude aether-gateway --exclude aether-data --all-targets -- -D warnings
- cargo nextest run -p aether-gateway
- cargo nextest run -p aether-data
- cargo nextest run --workspace --exclude aether-gateway --exclude aether-data
- cargo test -p aether-data sqlite --lib
- Postgres/MySQL data_db_smoke commands from rust-ci.yml

crates/aether-data/src/repository/settlement/postgres.rs

@@ -312,6 +312,7 @@ async fn consume_daily_quota_postgres(
     request_id: &str,
     total_cost_usd: f64,
     wallet_available_usd: Option<f64>,
+    wallet_can_overdraft: bool,
 ) -> Result<DailyQuotaDebitResult, DataLayerError> {
     if total_cost_usd <= 0.0 {
         return Ok(DailyQuotaDebitResult::default());
@@ -379,6 +380,7 @@ WHERE user_entitlement_id = $1
         });
     }
     if allow_wallet_overage
+        && !wallet_can_overdraft
         && wallet_available_usd.is_some_and(|available| {
             total_remaining + available + SETTLEMENT_EPSILON_USD < total_cost_usd
         })
@@ -560,6 +562,7 @@ LIMIT 1
                             None
                         };
 
+                        let wallet_can_overdraft = wallet_row.is_some();
                         let wallet_available_usd = match wallet_row.as_ref() {
                             Some(row) => {
                                 let limit_mode: String =
@@ -600,6 +603,7 @@ LIMIT 1
                                     &input.request_id,
                                     input.total_cost_usd,
                                     wallet_available_usd,
+                                    wallet_can_overdraft,
                                 )
                                 .await?;
                                 if quota.insufficient {
@@ -646,16 +650,8 @@ LIMIT 1
                                         before_gift,
                                         wallet_debit_cost_usd,
                                     );
-                                    if debit_plan.covered_usd() + SETTLEMENT_EPSILON_USD
-                                        < wallet_debit_cost_usd
-                                    {
-                                        final_billing_status = "insufficient_quota".to_string();
-                                        settlement.billing_status = final_billing_status.clone();
-                                    } else {
-                                        after_recharge =
-                                            before_recharge - debit_plan.recharge_deduction;
-                                        after_gift = before_gift - debit_plan.gift_deduction;
-                                    }
+                                    (after_recharge, after_gift) =
+                                        debit_plan.after_balances(before_recharge, before_gift);
                                 }
                                 if final_billing_status == "settled" {
                                     sqlx::query(