[Bug] Pulse v5: Auth/session not persisted after successful OTP link

[islandbitcoin]

Summary

After a successful OTP verification (user links account, sees @jabs + $23.03), the very next turn asking check my balance triggers a re-link prompt instead of using the authenticated session.

Observed behavior

1. User runs onboarding → OTP → succeeds → balance shown ✅
2. User immediately asks check my balance → asked to re-link ❌

Expected behavior

Linked state and auth token should persist across turns for the session lifetime.

Root cause hypothesis

Token/linked state written after OTP success is not reliably available on the next tool invocation. Likely a session hydration timing issue or the token is stored in a request-scoped context that doesn't carry forward.

Acceptance criteria

• After successful OTP, user can check balance, send, receive without re-linking
• Session persistence survives at least the conversation window
• Regression test: onboarding → OTP → balance → balance → send flow passes end-to-end

Notes

Hold for Dread go-ahead before implementation.