feat(tui): put the kawaii face+verb ticker in the status bar, not the thinking panel

The status bar was showing stale lifecycle text ("running…") while the
face+verb stream flickered through the thinking panel as Python pushed
thinking.delta events. That's backwards — the face ticker is the
primary "I'm alive" signal, it belongs in the status bar; the thinking
panel is for substantive reasoning and tool activity.

Status bar now reads `ui.busy`: when true, renders a local `<FaceTicker>`
cycling FACES × VERBS on a 2.5s interval, unaffected by server events.
When false, the bar shows the actual status string (ready, starting
agent…, interrupted, etc.).

Side effect: `scheduleThinkingStatus` still patches `ui.status` with
Python's face text, but while busy the bar ignores that string and uses
the ticker instead. No server-side changes needed — Python keeps
emitting thinking.delta as a liveness heartbeat, the TUI just doesn't
let it fight the status bar.

ui-tui/src/components/appLayout.tsx

@@ -138,6 +138,7 @@ const ComposerPane = memo(function ComposerPane({
         {ui.statusBar && (
           <StatusRule
             bgCount={ui.bgTasks.size}
+            busy={ui.busy}
             cols={composer.cols}
             cwdLabel={status.cwdLabel}
             model={ui.info?.model?.split('/').pop() ?? ''}
@@ -181,7 +182,7 @@ const ComposerPane = memo(function ComposerPane({
               {sh ? (
                 <Text color={ui.theme.color.shellDollar}>$ </Text>
               ) : (
-                <Text bold color={ui.theme.color.gold}>
+                <Text bold color={ui.theme.color.prompt}>
                   {composer.inputBuf.length ? '  ' : `${ui.theme.brand.prompt} `}
                 </Text>
               )}