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/services/compact/postCompactCleanup.ts

@@ -10,6 +10,17 @@ import { clearSessionMessagesCache } from '../../utils/sessionStorage.js'
 import { clearBetaTracingState } from '../../utils/telemetry/betaSessionTracing.js'
 import { resetMicrocompactState } from './microCompact.js'
 
+/**
+ * Compact-scoped cleanup callbacks registered by REPL or other long-lived
+ * components. Called during runPostCompactCleanup() so instance-scoped state
+ * (e.g. contentReplacementState) is freed alongside module-level caches.
+ */
+const compactCleanupCallbacks: Array<() => void> = []
+
+export function registerCompactCleanup(callback: () => void): void {
+  compactCleanupCallbacks.push(callback)
+}
+
 /**
  * Run cleanup of caches and tracking state after compaction.
  * Call this after both auto-compact and manual /compact to free memory
@@ -88,4 +99,11 @@ export function runPostCompactCleanup(querySource?: QuerySource): void {
       })
   }
   clearSessionMessagesCache()
+  for (const cb of compactCleanupCallbacks) {
+    try {
+      cb()
+    } catch (error) {
+      logError(error)
+    }
+  }
 }