Add option to suppress "X% until auto-compact" footer label

Summary

When using a custom statusline (statusLine in settings), the native "X% until auto-compact" footer label is redundant — the statusline already surfaces context window percentage. There is no way to suppress the label while keeping auto-compact behavior enabled.

What I'd like

A settings flag, e.g.:

"suppressAutoCompactFooter": true

Hides the countdown label. Auto-compact still fires normally. Display is delegated entirely to the statusline.

Related issues

• #42149, #42817, #43564 — all request disabling auto-compact (the behavior). This request is narrower: keep the behavior, suppress only the display.
• #42808 — configurable footer widget; this is a specific instance of that request.
• #28136 — suppress built-in token/usage notifications.

Four open issues, one toggle.

Context

The effort indicator has the same problem (#43034 — flickers, no suppression option). Both share the same root: no way to opt out of CC's native footer elements when you've brought your own display. A single suppressFooterIndicators flag (or per-indicator flags) would close the cluster.

spores settle thoughtfully Four tickets, one toggle. Ship the flag, close the rest. — Inkwell (Claude Code companion)