fix: flush held text-run carry on a 16ms timer so shell prompts render immediately

The highlight stream holds a trailing text run for cross-chunk anchor
consistency; a bare shell prompt (plain text, no follow-up data) stayed
held until the next keypress. Now the carry auto-flushes within one frame.

src/renderer/src/terminal/TerminalView.tsx

@@ -319,9 +319,23 @@ export const TerminalView: ForwardRefExoticComponent<TerminalViewProps & { ref?:
     // across a sessionId rebind (e.g. template apply).
     const stream = new HighlightStream(compiledRules)
     streamRef.current = stream
+    // The stream holds a trailing text run for cross-chunk anchor consistency.
+    // A shell prompt is exactly such a run with no follow-up data, so flush the
+    // carry on a short timer — prompts render within a frame, anchors survive.
+    let carryTimer: number | undefined
+    const scheduleCarryFlush = (): void => {
+      if (carryTimer !== undefined || !stream.hasPending()) return
+      carryTimer = window.setTimeout(() => {
+        carryTimer = undefined
+        if (deadRef.current) return
+        const rest = stream.flush()
+        if (rest) term.write(rest)
+      }, 16)
+    }
     const writeHighlighted = (data: string) => {
       const out = stream.push(data)
       if (out) term.write(out)
+      scheduleCarryFlush()
     }
     const disposables: { dispose(): void }[] = [
       term.onData((data) => {
@@ -375,6 +389,7 @@ export const TerminalView: ForwardRefExoticComponent<TerminalViewProps & { ref?:
     }
 
     return () => {
+      if (carryTimer !== undefined) window.clearTimeout(carryTimer)
       for (const unsubscribe of unsubscribes) unsubscribe()
       for (const disposable of disposables) disposable.dispose()
       observer?.disconnect()

src/renderer/src/terminal/highlightEngine.ts

@@ -240,6 +240,11 @@ export class HighlightStream {
     this.rules = rules
   }
 
+  /** True while content is held back (a pending flush will release it). */
+  hasPending(): boolean {
+    return this.buffer.length > 0
+  }
+
   /** Join held bytes with `chunk`, return content safe to hand to xterm. */
   push(chunk: string): string {
     this.buffer += chunk