docs: 合并性能分析报告并优化内存管理

将 performance-reporter.md 合入 memory-peak-analysis.md，统一分析文档。
代码优化包括：compact 峰值释放、GC 阈值触发、虚拟滚动参数调优、
HybridTransport 队列缩减、无界缓存加 LRU 淘汰、taskSummary 避免数组拷贝。

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

src/bootstrap/state.ts

@@ -1463,6 +1463,16 @@ export function getPlanSlugCache(): Map<string, string> {
   return STATE.planSlugCache
 }
 
+export function setPlanSlugCacheEntry(sessionId: string, slug: string): void {
+  if (STATE.planSlugCache.size >= 50) {
+    const firstKey = STATE.planSlugCache.keys().next().value
+    if (firstKey !== undefined) {
+      STATE.planSlugCache.delete(firstKey)
+    }
+  }
+  STATE.planSlugCache.set(sessionId, slug)
+}
+
 export function getSessionCreatedTeams(): Set<string> {
   return STATE.sessionCreatedTeams
 }
@@ -1640,6 +1650,12 @@ export function setSystemPromptSectionCacheEntry(
   name: string,
   value: string | null,
 ): void {
+  if (STATE.systemPromptSectionCache.size >= 100) {
+    const firstKey = STATE.systemPromptSectionCache.keys().next().value
+    if (firstKey !== undefined) {
+      STATE.systemPromptSectionCache.delete(firstKey)
+    }
+  }
   STATE.systemPromptSectionCache.set(name, value)
 }
 

src/cli/print.ts

@@ -551,9 +551,19 @@ export async function runHeadless(
     proactiveModule.activateProactive('command')
   }
 
-  // Periodically force a full GC to keep memory usage in check
+  // Periodically run GC to keep memory usage in check.
+  // Uses a memory threshold to trigger a forced (major) GC when RSS grows
+  // beyond 350MB — the incremental GC may not reclaim enough during peaks
+  // (compact, long sessions with many mounted DOM nodes).
   if (typeof Bun !== 'undefined') {
-    const gcTimer = setInterval(Bun.gc, 1000)
+    const gcTimer = setInterval(() => {
+      const rss = process.memoryUsage.rss()
+      if (rss > 350 * 1024 * 1024) {
+        Bun.gc(true)
+      } else {
+        Bun.gc(false)
+      }
+    }, 1000)
     gcTimer.unref()
   }
 

src/cli/transports/HybridTransport.ts

@@ -83,7 +83,7 @@ export class HybridTransport extends WebSocketTransport {
       // SerialBatchEventUploader backpressure check). So set it high enough
       // to be a memory bound only. Wire real backpressure in a follow-up
       // once callers await.
-      maxQueueSize: 100_000,
+      maxQueueSize: 10_000,
       baseDelayMs: 500,
       maxDelayMs: 8000,
       jitterMs: 1000,

src/hooks/useVirtualScroll.ts

@@ -20,7 +20,7 @@ const DEFAULT_ESTIMATE = 3
  * Extra rows rendered above and below the viewport. Generous because real
  * heights can be 10x the estimate for long tool results.
  */
-const OVERSCAN_ROWS = 80
+const OVERSCAN_ROWS = 40
 /** Items rendered before the ScrollBox has laid out (viewportHeight=0). */
 const COLD_START_COUNT = 30
 /**
@@ -43,7 +43,7 @@ const SCROLL_QUANTUM = OVERSCAN_ROWS >> 1
  */
 const PESSIMISTIC_HEIGHT = 1
 /** Cap on mounted items to bound fiber allocation even in degenerate cases. */
-const MAX_MOUNTED_ITEMS = 300
+const MAX_MOUNTED_ITEMS = 200
 /**
  * Max NEW items to mount in a single commit. Scrolling into a fresh range
  * with PESSIMISTIC_HEIGHT=1 would mount 194 items at once (OVERSCAN_ROWS*2+

src/services/compact/compact.ts

@@ -521,7 +521,7 @@ export async function compactConversation(
     }
 
     // Store the current file state before clearing
-    const preCompactReadFileState = cacheToObject(context.readFileState)
+    let preCompactReadFileState = cacheToObject(context.readFileState)
 
     // Clear the cache
     context.readFileState.clear()
@@ -543,6 +543,9 @@ export async function compactConversation(
       ),
       createAsyncAgentAttachmentsIfNeeded(context),
     ])
+    // Release the readFileState snapshot — it can hold 25+ MB of file content
+    preCompactReadFileState =
+      undefined as unknown as typeof preCompactReadFileState
 
     const postCompactFileAttachments: AttachmentMessage[] = [
       ...fileAttachments,
@@ -649,6 +652,8 @@ export async function compactConversation(
 
     // Extract compaction API usage metrics
     const compactionUsage = getTokenUsage(summaryResponse)
+    // Release the full API response — it holds content blocks + usage metadata
+    summaryResponse = undefined as unknown as typeof summaryResponse
 
     const querySourceForEvent =
       recompactionInfo?.querySource ?? context.options.querySource ?? 'unknown'
@@ -922,7 +927,7 @@ export async function partialCompactConversation(
     }
 
     // Store the current file state before clearing
-    const preCompactReadFileState = cacheToObject(context.readFileState)
+    let preCompactReadFileState = cacheToObject(context.readFileState)
     context.readFileState.clear()
     context.loadedNestedMemoryPaths?.clear()
     // Intentionally NOT resetting sentSkillNames — see compactConversation()
@@ -937,6 +942,9 @@ export async function partialCompactConversation(
       ),
       createAsyncAgentAttachmentsIfNeeded(context),
     ])
+    // Release the readFileState snapshot — it can hold 25+ MB of file content
+    preCompactReadFileState =
+      undefined as unknown as typeof preCompactReadFileState
 
     const postCompactFileAttachments: AttachmentMessage[] = [
       ...fileAttachments,
@@ -992,6 +1000,8 @@ export async function partialCompactConversation(
       summaryResponse,
     ])
     const compactionUsage = getTokenUsage(summaryResponse)
+    // Release the full API response — it holds content blocks + usage metadata
+    summaryResponse = undefined as unknown as typeof summaryResponse
 
     logEvent('tengu_partial_compact', {
       preCompactTokenCount,

src/utils/plans.ts

@@ -10,7 +10,11 @@ import type {
   SystemFileSnapshotMessage,
   UserMessage,
 } from 'src/types/message.js'
-import { getPlanSlugCache, getSessionId } from '../bootstrap/state.js'
+import {
+  getPlanSlugCache,
+  getSessionId,
+  setPlanSlugCacheEntry,
+} from '../bootstrap/state.js'
 import { EXIT_PLAN_MODE_V2_TOOL_NAME } from '@claude-code-best/builtin-tools/tools/ExitPlanModeTool/constants.js'
 import { getCwd } from './cwd.js'
 import { logForDebugging } from './debug.js'
@@ -43,7 +47,7 @@ export function getPlanSlug(sessionId?: SessionId): string {
         break
       }
     }
-    cache.set(id, slug!)
+    setPlanSlugCacheEntry(id, slug!)
   }
   return slug!
 }
@@ -52,7 +56,7 @@ export function getPlanSlug(sessionId?: SessionId): string {
  * Set a specific plan slug for a session (used when resuming a session)
  */
 export function setPlanSlug(sessionId: SessionId, slug: string): void {
-  getPlanSlugCache().set(sessionId, slug)
+  setPlanSlugCacheEntry(sessionId, slug)
 }
 
 /**

src/utils/taskSummary.ts

@@ -44,9 +44,13 @@ export function maybeGenerateTaskSummary(
     if (!messages || messages.length === 0) return
 
     // Extract a short status from the most recent assistant message
-    const lastAssistant = [...messages]
-      .reverse()
-      .find(m => m.type === 'assistant')
+    let lastAssistant: (typeof messages)[0] | undefined
+    for (let i = messages.length - 1; i >= 0; i--) {
+      if (messages[i]!.type === 'assistant') {
+        lastAssistant = messages[i]
+        break
+      }
+    }
 
     let status: 'busy' | 'idle' = 'busy'
     let waitingFor: string | undefined