feat(cli,cloud): QR code at startup + relay keepalive fix

[koistya]

Summary

• QR code: Print a half-block Unicode QR code below the Quick Connect URL at daemon startup. Skipped silently when the terminal is too narrow or encodeQR throws — startup is never blocked.
• Relay keepalive (daemon): Send SBRP Ping every 45s in runMux to keep the daemon's relay connection alive past the relay's 90s idle sweep; cleared in finally on disconnect.
• Relay keepalive (client): Fix timer race in connect.ts — capture the interval handle in a local const timer so a stale send failure from a prior connection cannot clear the active connection's timer; terminate() now clears explicitly before transport close.
• ADR-019: Documents trust policy defaults ("auto") for both QC and account auth paths and the future path to "pinned-only" once expectedFingerprint is plumbed through the account API.
• npm TypeScript badge: Added types and exports fields to packages/cli/package.json so the package shows the TypeScript icon on npm.

QR output

  Quick Connect: https://sideband.cloud/connect#qc=abcd-efgh-ijkl
  Code:          abcd-efgh-ijkl

  Scan to connect:
  ████████████████████████████████
  ██ ▄▄▄▄▄ █▀▄ █▄▀▄▀▄▄▀ █ ▄▄▄▄▄ ██
  ██ █   █ █▀▀▄█▄▄█▄▀ ▀▄█ █   █ ██
  ██ █▄▄▄█ █▀▄▀▄▀▀▄▀▄▄▄▀█ █▄▄▄█ ██
  ████████████████████████████████

  Waiting for connections...

Test plan

• bun test packages/cli — QR width-guard and emitError tests pass
• Start daemon with a wide terminal: QR appears below the URL
• Start daemon with a narrow terminal (< matrix width + 2): QR silently absent
• Leave a cloud-connected daemon idle for >90s: connection stays alive
• Verify npm package page shows the TypeScript icon after publish