revert: 移除主屏幕周期性 self-healing 重绘

回退 f69c7051 中引入的 ink.tsx self-healing 机制（lastMainScreenHealTime 字段
+ 每 5 秒触发全量重绘 + needsEraseBeforePaint 主屏幕分支）。该机制在 workflow
面板持续刷新场景下表现为可见的"重复刷新"，且修复效果不稳定。

alt-screen 的 needsEraseBeforePaint 路径和 prevFrameContaminated 字段保留，
它们仍服务于 handleResize / layout shift / selection 高亮。

Co-Authored-By: glm-5.2 <zai-org@claude-code-best.win>

packages/@ant/ink/src/core/ink.tsx

@@ -165,12 +165,6 @@ export default class Ink {
   private frontFrame: Frame;
   private backFrame: Frame;
   private lastPoolResetTime = performance.now();
-  /** Timestamp of last periodic full-redraw in main screen mode. Used to
-   *  recover from accumulated cursor drift / blit ghosting. Wall-clock
-   *  based (not frame-count) so drain scroll frames (250fps) don't
-   *  accelerate the cycle. Alt-screen doesn't need this — CSI H resets
-   *  cursor every frame. */
-  private lastMainScreenHealTime = performance.now();
   private drainTimer: ReturnType<typeof setTimeout> | null = null;
   private lastYogaCounters: {
     ms: number;
@@ -527,25 +521,7 @@ export default class Ink {
     // an extra React re-render cycle.
     this.options.onBeforeRender?.();
 
-    // Periodic self-healing: every ~5s in main screen mode, force a full
-    // terminal redraw to recover from accumulated cursor drift / blit
-    // ghosting. Alt-screen doesn't need this — CSI H resets cursor to
-    // (0,0) every frame. Wall-clock based so drain scroll frames (250fps)
-    // don't accelerate the cycle. Guarded by isTTY so ANSI escape
-    // sequences are not leaked into pipes / redirected output.
     const renderStart = performance.now();
-    if (
-      !this.altScreenActive &&
-      !this.isPaused &&
-      this.options.stdout.isTTY &&
-      renderStart - this.lastMainScreenHealTime > 5000
-    ) {
-      this.lastMainScreenHealTime = renderStart;
-      this.repaint();
-      this.prevFrameContaminated = true;
-      this.needsEraseBeforePaint = true;
-    }
-
     const terminalWidth = this.options.stdout.columns || 80;
     const terminalRows = this.options.stdout.rows || 24;
 
@@ -780,13 +756,6 @@ export default class Ink {
         optimized.unshift(CURSOR_HOME_PATCH);
       }
       optimized.push(this.altScreenParkPatch);
-    } else if (this.needsEraseBeforePaint && hasDiff) {
-      // Main-screen periodic self-healing: clear visible terminal before
-      // painting the diff. Without this, rows past the new frame's height
-      // would retain stale content from the previous frame. BSU/ESU keeps
-      // old content visible until the full erase+paint is flushed atomically.
-      this.needsEraseBeforePaint = false;
-      optimized.unshift(ERASE_THEN_HOME_PATCH);
     }
 
     // Native cursor positioning: park the terminal cursor at the declared