fix: 内存优化 — 预测性 compact 阈值、增量 lookups orphaned 修复、deferred slice 引用优化

- P0: REPL.tsx 用 useMemo 包裹 deferred messages slice，避免每次渲染创建新数组引用导致不必要的后台重渲染
- P1: 预测性 compact 阈值改用 effectiveContextWindow - growth，消除与 autocompact buffer 的双重预留；TOOL_RESULT_GROWTH_ESTIMATE 从 20K 降至 15K
- P2: 增量 lookups 增加 lastAssistantMsgId 一致性检查和 orphaned server_tool_use/mcp_tool_use 扫描，防止 UI 永久 loading
- P3: reactiveCompact 类型断言改为直接使用 'compact' 字面量
- docs: CLAUDE.md 统一使用 precheck 替代分散的 typecheck/lint/test 命令

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

src/services/compact/compact.ts

@@ -334,13 +334,12 @@ export type RecompactionInfo = {
  * Order: boundaryMarker, summaryMessages, messagesToKeep, attachments, hookResults
  */
 export function buildPostCompactMessages(result: CompactionResult): Message[] {
-  return [
-    result.boundaryMarker,
-    ...result.summaryMessages,
-    ...(result.messagesToKeep ?? []),
-    ...result.attachments,
-    ...result.hookResults,
-  ]
+  return ([result.boundaryMarker] as Message[]).concat(
+    result.summaryMessages,
+    result.messagesToKeep ?? [],
+    result.attachments,
+    result.hookResults,
+  )
 }
 
 /**