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

frontend/src/i18n/locales/en.ts

@@ -1734,6 +1734,10 @@ export default {
           stickyExemptWarning: 'RPM limit (Sticky Exempt) - Approaching limit',
           stickyExemptOver: 'RPM limit (Sticky Exempt) - Over limit, sticky only'
         },
+        quota: {
+          exceeded: 'Quota exceeded, account paused',
+          normal: 'Quota normal'
+        },
       },
       tempUnschedulable: {
         title: 'Temp Unschedulable',
@@ -1779,6 +1783,10 @@ export default {
         }
       },
       clearRateLimit: 'Clear Rate Limit',
+      resetQuota: 'Reset Quota',
+      quotaLimit: 'Quota Limit',
+      quotaLimitPlaceholder: '0 means unlimited',
+      quotaLimitHint: 'Set max spending limit (USD). Account will be paused when reached. Changing limit won\'t reset usage.',
       testConnection: 'Test Connection',
       reAuthorize: 'Re-Authorize',
       refreshToken: 'Refresh Token',