fix(tui): repainted ssh topology flips

- Added renderer hooks for first-result placeholder replacement and partial-result settle repaints.\n- Enabled the hooks for SSH and covered the streamed-placeholder and settle seams.\n\nFixes #4314

packages/coding-agent/src/tools/renderers.ts

@@ -63,6 +63,19 @@ export type ToolRenderer = {
 	 * with the final render and may commit like any settled stream.
 	 */
 	provisionalPartialResult?: boolean;
+	/**
+	 * Whether replacing a streamed pending placeholder with the first result
+	 * requires a full viewport repaint. Use for merged renderers whose pending
+	 * streamed args may have committed placeholder rows that the result render
+	 * re-anchors instead of preserving.
+	 */
+	forceFirstResultViewportRepaint?: boolean;
+	/**
+	 * Whether settling a provisional partial result into the final render requires
+	 * a full viewport repaint. Use when the result renderer changes chrome or
+	 * frame topology at `options.isPartial: true -> false`.
+	 */
+	forceResultViewportRepaintOnSettle?: boolean;
 };
 
 export const toolRenderers: Record<string, ToolRenderer> = {

packages/coding-agent/src/tools/ssh.ts

@@ -392,4 +392,12 @@ export const sshToolRenderer = {
 	// land below and strand a duplicate pending header above the final frame
 	// ([#3177](https://github.com/can1357/oh-my-pi/issues/3177)).
 	provisionalPartialResult: true,
+	// Streamed args can initially render the SSH placeholder (`⏳ SSH: […]` /
+	// `$ …`), then the first partial result inserts the `Output` section and
+	// re-anchors the frame. Force a full repaint at that seam so placeholder rows
+	// do not survive in viewport/native scrollback.
+	forceFirstResultViewportRepaint: true,
+	// The provisional pending-result frame settles into the final `⇄ SSH: [host]`
+	// frame, so clear/replay the viewport at that topology flip too.
+	forceResultViewportRepaintOnSettle: true,
 };