feat(tui): show running cron status in footer

[ousamabenyounes]

Related Issue

Resolve #2173

Problem

Scheduled prompts run in the background without any footer indication. A user cannot tell whether a cron-triggered turn is currently active, unlike background shell tasks and agents.

What changed

• show a [cron running] badge in the existing footer task slot while scheduled work is active;
• handle both an idle cron that starts its own turn and a cron fire steered into an already-running user turn;
• clear the badge on every turn-ending reason and when session runtime state resets;
• document the badge in the English and Chinese scheduled-task reference.

Test verification (RED → GREEN)

• RED on the unpatched path: the footer regression tests failed because cron status rendering did not exist.
• RED for the active-turn edge case: user turn.started → cron.fired → same turn continues did not render [cron running].
• GREEN after the patch: component and event-routing tests cover hidden, active, coexistence, independent clearing, idle cron turns, active-turn steering, and turn completion.
• Full local suite proof on Node 24.15.0 after rebasing onto current main: 185 test files passed, 2 skipped; 2,456 tests passed, 5 pre-existing skips, 0 failed.
• CLI typecheck, changed-file type-aware lint (0 errors), sherif, changeset validation, docs build, and git diff --check pass.

Checklist

• I have read the CONTRIBUTING document.
• I have linked a related issue, or explained the problem above.
• I have added tests that prove my feature works.
• Ran gen-changesets skill, or this PR needs no changeset.
• Ran gen-docs skill, or this PR needs no doc update.

[changeset-bot]

🦋 Changeset detected

Latest commit: 5763bee

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@moonshot-ai/kimi-code	Patch

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