refactor: rename anthropic-auto-compact to anthropic-context-window-limit-recovery

The old name 'auto-compact' was misleading - the hook does much more than
just compaction. It's a full recovery pipeline for context window limit
errors including:
- DCP (Dynamic Context Pruning)
- Aggressive/single truncation
- Summarize with retry
- Emergency message revert

The new name accurately describes its purpose: recovering from Anthropic
context window limit exceeded errors.

🤖 GENERATED WITH ASSISTANCE OF [OhMyOpenCode](https://github.com/code-yeongyu/oh-my-opencode)

src/hooks/anthropic-context-window-limit-recovery/pruning-deduplication.ts

@@ -0,0 +1,184 @@
+import { existsSync, readdirSync, readFileSync } from "node:fs"
+import { join } from "node:path"
+import type { PruningState, ToolCallSignature } from "./pruning-types"
+import { estimateTokens } from "./pruning-types"
+import { log } from "../../shared/logger"
+import { MESSAGE_STORAGE } from "../../features/hook-message-injector"
+
+export interface DeduplicationConfig {
+  enabled: boolean
+  protectedTools?: string[]
+}
+
+interface ToolPart {
+  type: string
+  callID?: string
+  tool?: string
+  state?: {
+    input?: unknown
+    output?: string
+  }
+}
+
+interface MessagePart {
+  type: string
+  parts?: ToolPart[]
+}
+
+export function createToolSignature(toolName: string, input: unknown): string {
+  const sortedInput = sortObject(input)
+  return `${toolName}::${JSON.stringify(sortedInput)}`
+}
+
+function sortObject(obj: unknown): unknown {
+  if (obj === null || obj === undefined) return obj
+  if (typeof obj !== "object") return obj
+  if (Array.isArray(obj)) return obj.map(sortObject)
+  
+  const sorted: Record<string, unknown> = {}
+  const keys = Object.keys(obj as Record<string, unknown>).sort()
+  for (const key of keys) {
+    sorted[key] = sortObject((obj as Record<string, unknown>)[key])
+  }
+  return sorted
+}
+
+function getMessageDir(sessionID: string): string | null {
+  if (!existsSync(MESSAGE_STORAGE)) return null
+
+  const directPath = join(MESSAGE_STORAGE, sessionID)
+  if (existsSync(directPath)) return directPath
+
+  for (const dir of readdirSync(MESSAGE_STORAGE)) {
+    const sessionPath = join(MESSAGE_STORAGE, dir, sessionID)
+    if (existsSync(sessionPath)) return sessionPath
+  }
+
+  return null
+}
+
+function readMessages(sessionID: string): MessagePart[] {
+  const messageDir = getMessageDir(sessionID)
+  if (!messageDir) return []
+
+  const messages: MessagePart[] = []
+  
+  try {
+    const files = readdirSync(messageDir).filter(f => f.endsWith(".json"))
+    for (const file of files) {
+      const content = readFileSync(join(messageDir, file), "utf-8")
+      const data = JSON.parse(content)
+      if (data.parts) {
+        messages.push(data)
+      }
+    }
+  } catch {
+    return []
+  }
+
+  return messages
+}
+
+export function executeDeduplication(
+  sessionID: string,
+  state: PruningState,
+  config: DeduplicationConfig,
+  protectedTools: Set<string>
+): number {
+  if (!config.enabled) return 0
+
+  const messages = readMessages(sessionID)
+  const signatures = new Map<string, ToolCallSignature[]>()
+  
+  let currentTurn = 0
+  
+  for (const msg of messages) {
+    if (!msg.parts) continue
+    
+    for (const part of msg.parts) {
+      if (part.type === "step-start") {
+        currentTurn++
+        continue
+      }
+      
+      if (part.type !== "tool" || !part.callID || !part.tool) continue
+      
+      if (protectedTools.has(part.tool)) continue
+      
+      if (config.protectedTools?.includes(part.tool)) continue
+      
+      if (state.toolIdsToPrune.has(part.callID)) continue
+      
+      const signature = createToolSignature(part.tool, part.state?.input)
+      
+      if (!signatures.has(signature)) {
+        signatures.set(signature, [])
+      }
+      
+      signatures.get(signature)!.push({
+        toolName: part.tool,
+        signature,
+        callID: part.callID,
+        turn: currentTurn,
+      })
+      
+      if (!state.toolSignatures.has(signature)) {
+        state.toolSignatures.set(signature, [])
+      }
+      state.toolSignatures.get(signature)!.push({
+        toolName: part.tool,
+        signature,
+        callID: part.callID,
+        turn: currentTurn,
+      })
+    }
+  }
+  
+  let prunedCount = 0
+  let tokensSaved = 0
+  
+  for (const [signature, calls] of signatures) {
+    if (calls.length > 1) {
+      const toPrune = calls.slice(0, -1)
+      
+      for (const call of toPrune) {
+        state.toolIdsToPrune.add(call.callID)
+        prunedCount++
+        
+        const output = findToolOutput(messages, call.callID)
+        if (output) {
+          tokensSaved += estimateTokens(output)
+        }
+        
+        log("[pruning-deduplication] pruned duplicate", {
+          tool: call.toolName,
+          callID: call.callID,
+          turn: call.turn,
+          signature: signature.substring(0, 100),
+        })
+      }
+    }
+  }
+  
+  log("[pruning-deduplication] complete", {
+    prunedCount,
+    tokensSaved,
+    uniqueSignatures: signatures.size,
+  })
+  
+  return prunedCount
+}
+
+function findToolOutput(messages: MessagePart[], callID: string): string | null {
+  for (const msg of messages) {
+    if (!msg.parts) continue
+    
+    for (const part of msg.parts) {
+      if (part.type === "tool" && part.callID === callID && part.state?.output) {
+        return part.state.output
+      }
+    }
+  }
+  
+  return null
+}