fix: wire deduplication into compaction recovery for prompt-too-long errors (#96)

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-opencode)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

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

@@ -0,0 +1,71 @@
+import type { ParsedTokenLimitError } from "./types"
+import type { ExperimentalConfig } from "../../config"
+import type { DeduplicationConfig } from "./pruning-deduplication"
+import type { PruningState } from "./pruning-types"
+import { executeDeduplication } from "./pruning-deduplication"
+import { truncateToolOutputsByCallId } from "./pruning-tool-output-truncation"
+import { log } from "../../shared/logger"
+
+function createPruningState(): PruningState {
+  return {
+    toolIdsToPrune: new Set<string>(),
+    currentTurn: 0,
+    fileOperations: new Map(),
+    toolSignatures: new Map(),
+    erroredTools: new Map(),
+  }
+}
+
+function isPromptTooLongError(parsed: ParsedTokenLimitError): boolean {
+  return !parsed.errorType.toLowerCase().includes("non-empty content")
+}
+
+function getDeduplicationPlan(
+  experimental?: ExperimentalConfig,
+): { config: DeduplicationConfig; protectedTools: Set<string> } | null {
+  const pruningConfig = experimental?.dynamic_context_pruning
+  if (!pruningConfig?.enabled) return null
+
+  const deduplicationEnabled = pruningConfig.strategies?.deduplication?.enabled
+  if (deduplicationEnabled === false) return null
+
+  const protectedTools = new Set(pruningConfig.protected_tools ?? [])
+  return {
+    config: {
+      enabled: true,
+      protectedTools: pruningConfig.protected_tools ?? [],
+    },
+    protectedTools,
+  }
+}
+
+export async function attemptDeduplicationRecovery(
+  sessionID: string,
+  parsed: ParsedTokenLimitError,
+  experimental: ExperimentalConfig | undefined,
+): Promise<void> {
+  if (!isPromptTooLongError(parsed)) return
+
+  const plan = getDeduplicationPlan(experimental)
+  if (!plan) return
+
+  const pruningState = createPruningState()
+  const prunedCount = executeDeduplication(
+    sessionID,
+    pruningState,
+    plan.config,
+    plan.protectedTools,
+  )
+  const { truncatedCount } = truncateToolOutputsByCallId(
+    sessionID,
+    pruningState.toolIdsToPrune,
+  )
+
+  if (prunedCount > 0 || truncatedCount > 0) {
+    log("[auto-compact] deduplication recovery applied", {
+      sessionID,
+      prunedCount,
+      truncatedCount,
+    })
+  }
+}