fix(claude-code-hooks): cache idle hook config and parent lookups

Reduce repeated session.idle work by reusing hook config loads across a short TTL and by retrying parent session lookup instead of permanently caching transient failures.

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

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

src/hooks/claude-code-hooks/config-loader.ts

@@ -4,6 +4,8 @@ import type { ClaudeHookEvent } from "./types"
 import { log } from "../../shared/logger"
 import { getOpenCodeConfigDir } from "../../shared"
 
+const CONFIG_CACHE_TTL_MS = 30_000
+
 export interface DisabledHooksConfig {
   Stop?: string[]
   PreToolUse?: string[]
@@ -16,12 +18,40 @@ export interface PluginExtendedConfig {
   disabledHooks?: DisabledHooksConfig
 }
 
+interface PluginExtendedConfigCacheEntry {
+  value: PluginExtendedConfig
+  cachedAt: number
+}
+
 const USER_CONFIG_PATH = join(getOpenCodeConfigDir({ binary: "opencode" }), "opencode-cc-plugin.json")
+const configCache = new Map<string, PluginExtendedConfigCacheEntry>()
 
 function getProjectConfigPath(): string {
   return join(process.cwd(), ".opencode", "opencode-cc-plugin.json")
 }
 
+function getCacheKey(): string {
+  return process.cwd()
+}
+
+function getCachedConfig(cacheKey: string): PluginExtendedConfig | undefined {
+  const cachedEntry = configCache.get(cacheKey)
+  if (!cachedEntry) {
+    return undefined
+  }
+
+  if (Date.now() - cachedEntry.cachedAt >= CONFIG_CACHE_TTL_MS) {
+    configCache.delete(cacheKey)
+    return undefined
+  }
+
+  return cachedEntry.value
+}
+
+export function clearPluginExtendedConfigCache(): void {
+  configCache.clear()
+}
+
 async function loadConfigFromPath(path: string): Promise<PluginExtendedConfig | null> {
   if (!existsSync(path)) {
     return null
@@ -53,6 +83,12 @@ function mergeDisabledHooks(
 }
 
 export async function loadPluginExtendedConfig(): Promise<PluginExtendedConfig> {
+  const cacheKey = getCacheKey()
+  const cachedConfig = getCachedConfig(cacheKey)
+  if (cachedConfig) {
+    return cachedConfig
+  }
+
   const userConfig = await loadConfigFromPath(USER_CONFIG_PATH)
   const projectConfig = await loadConfigFromPath(getProjectConfigPath())
 
@@ -71,6 +107,11 @@ export async function loadPluginExtendedConfig(): Promise<PluginExtendedConfig>
     })
   }
 
+  configCache.set(cacheKey, {
+    value: merged,
+    cachedAt: Date.now(),
+  })
+
   return merged
 }