fix: 修复内存溢出问题，compact 时清理持久增长数据结构

- compact 时清理 contentReplacementState（seenIds/replacements）
- logError() 使用 shortErrorStack 替代完整 err.stack，减少 GC 压力
- permissionDenials 每次 submitMessage 清空，防止无限增长
- SSE 缓冲区添加 1MB 上限，防止畸形数据无限累积

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/screens/REPL.tsx

@@ -305,8 +305,9 @@ import {
 import { deserializeMessages } from '../utils/conversationRecovery.js';
 import { extractReadFilesFromMessages, extractBashToolsFromMessages } from '../utils/queryHelpers.js';
 import { resetMicrocompactState } from '../services/compact/microCompact.js';
-import { runPostCompactCleanup } from '../services/compact/postCompactCleanup.js';
+import { runPostCompactCleanup, registerCompactCleanup } from '../services/compact/postCompactCleanup.js';
 import {
+  createContentReplacementState,
   provisionContentReplacementState,
   reconstructContentReplacementState,
   type ContentReplacementRecord,
@@ -1778,6 +1779,9 @@ export function REPL({
   const [contentReplacementStateRef] = useState(() => ({
     current: provisionContentReplacementState(initialMessages, initialContentReplacements),
   }));
+  registerCompactCleanup(() => {
+    contentReplacementStateRef.current = createContentReplacementState();
+  });
 
   const [haveShownCostDialog, setHaveShownCostDialog] = useState(getGlobalConfig().hasAcknowledgedCostThreshold);
   const [vimMode, setVimMode] = useState<VimMode>('INSERT');