feat(api-key): add independent quota and expiration support

This feature allows API Keys to have their own quota limits and expiration
times, independent of the user's balance.

Backend:
- Add quota, quota_used, expires_at fields to api_key schema
- Implement IsExpired() and IsQuotaExhausted() checks in middleware
- Add ResetQuota and ClearExpiration API endpoints
- Integrate quota billing in gateway handlers (OpenAI, Anthropic, Gemini)
- Include quota/expiration fields in auth cache for performance
- Expiration check returns 403, quota exhausted returns 429

Frontend:
- Add quota and expiration inputs to key create/edit dialog
- Add quick-select buttons for expiration (+7, +30, +90 days)
- Add reset quota confirmation dialog
- Add expires_at column to keys list
- Add i18n translations for new features (en/zh)

Migration:
- Add 045_add_api_key_quota.sql for new columns

backend/ent/runtime/runtime.go

@@ -91,6 +91,14 @@ func init() {
 	apikey.DefaultStatus = apikeyDescStatus.Default.(string)
 	// apikey.StatusValidator is a validator for the "status" field. It is called by the builders before save.
 	apikey.StatusValidator = apikeyDescStatus.Validators[0].(func(string) error)
+	// apikeyDescQuota is the schema descriptor for quota field.
+	apikeyDescQuota := apikeyFields[7].Descriptor()
+	// apikey.DefaultQuota holds the default value on creation for the quota field.
+	apikey.DefaultQuota = apikeyDescQuota.Default.(float64)
+	// apikeyDescQuotaUsed is the schema descriptor for quota_used field.
+	apikeyDescQuotaUsed := apikeyFields[8].Descriptor()
+	// apikey.DefaultQuotaUsed holds the default value on creation for the quota_used field.
+	apikey.DefaultQuotaUsed = apikeyDescQuotaUsed.Default.(float64)
 	accountMixin := schema.Account{}.Mixin()
 	accountMixinHooks1 := accountMixin[1].Hooks()
 	account.Hooks[0] = accountMixinHooks1[0]