Add a "Bulk Add" button on /dashboard/providers/codex that imports
multiple OAuth accounts at once by pasting a JSON array, single object,
or { accounts: [...] } wrapper.
- New endpoint POST /api/oauth/codex/bulk-import (serial loop, no token echo)
- New BulkImportCodexModal component with JSON textarea + success/failure summary
- Persist idToken/lastRefreshAt on first insert via OPTIONAL_FIELDS
- Backfill email/chatgptAccountId/chatgptPlanType from JWT when missing
- Derive expiresAt from expiresIn when missing
- Gated to providerId === "codex" only; other providers unaffected
Co-authored-by: Cursor <cursoragent@cursor.com>
