feat: add quota limit for API key accounts

- Add configurable spending limit (quota_limit) for apikey-type accounts
- Atomic quota accumulation via PostgreSQL JSONB operations on TotalCost
- Scheduler filters out over-quota accounts with outbox-triggered snapshot refresh
- Display quota usage ($used / $limit) in account capacity column
- Add "Reset Quota" action in account menu to reset usage to zero
- Editing account settings preserves quota_used (no accidental reset)
- Covers all 3 billing paths: Anthropic, Gemini, OpenAI RecordUsage

chore: bump version to 0.1.90.4

backend/internal/service/account_service.go

@@ -68,6 +68,10 @@ type AccountRepository interface {
 	UpdateSessionWindow(ctx context.Context, id int64, start, end *time.Time, status string) error
 	UpdateExtra(ctx context.Context, id int64, updates map[string]any) error
 	BulkUpdate(ctx context.Context, ids []int64, updates AccountBulkUpdate) (int64, error)
+	// IncrementQuotaUsed 原子递增 API Key 账号的配额用量
+	IncrementQuotaUsed(ctx context.Context, id int64, amount float64) error
+	// ResetQuotaUsed 重置 API Key 账号的配额用量为 0
+	ResetQuotaUsed(ctx context.Context, id int64) error
 }
 
 // AccountBulkUpdate describes the fields that can be updated in a bulk operation.