Surface it to the user when the partner run gate suppresses auto-queue

# Surface it to the user when the partner run gate suppresses auto-queue

## Context
With Run-on-change active and a partner node in the graph while signed out, the partner run gate (#15248) suppresses auto-queue submissions. That suppression is silent today: no toast, no state change on the Run button beyond the sign-in swap — the user's auto-queue just stops firing.

Telemetry now records each suppression (`partner_run_gate_blocked`, `trigger: auto-queue`), but the user themselves gets no signal.

## Ask
Show a lightweight, non-spammy notice the first time auto-queue is suppressed in a session — e.g. a toast "Auto-queue paused: sign in to run partner nodes" — cleared when the gate lifts. Debounce so a burst of change events produces one notice, not one per edit.

Flagged as a UX gap (follow-up, not blocking) in #15248 review: https://github.com/Comfy-Org/ComfyUI_frontend/pull/15248#issuecomment-5492415110

Start at the partner run gate described in #15248 and trace the auto-queue and Run button path that records partner_run_gate_blocked with trigger: auto-queue. Review the existing toast and session-state handling before adding the notice behavior; done means one debounced notice appears while signed out, clears when the gate lifts, and does not repeat for every change event.

Written by the indexing model from the issue text.