feat: persist account quota state

[caigee-cmd]

Summary

• persist account quota snapshots and quota-exhausted state in SQLite
• stop refreshing every account on Accounts page load; use stored state for filtering and pagination
• add compact provider filters and default 20 accounts per page
• simplify Access page endpoint and connection presentation
• tolerate completed Qoder SSE streams without a final [DONE] marker when a finish reason was received

Validation

• go test ./...
• cd frontend && npm run sync
• cd frontend && npm run lint
• python3 scripts/release-notes.py validate