refactor(index): use migration module from shared

Removes inline migration logic from index.ts and imports from shared/migration module.
This completes the refactoring to extract testable migration logic into a dedicated module.

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

Author: code-yeongyu

src/index.ts

@@ -61,103 +61,11 @@ import { builtinTools, createCallOmoAgent, createBackgroundTools, createLookAt,
 import { BackgroundManager } from "./features/background-agent";
 import { createBuiltinMcps } from "./mcp";
 import { OhMyOpenCodeConfigSchema, type OhMyOpenCodeConfig, type HookName } from "./config";
-import { log, deepMerge, getUserConfigDir, addConfigLoadError, parseJsonc, detectConfigFile } from "./shared";
+import { log, deepMerge, getUserConfigDir, addConfigLoadError, parseJsonc, detectConfigFile, migrateConfigFile } from "./shared";
 import { PLAN_SYSTEM_PROMPT, PLAN_PERMISSION } from "./agents/plan-prompt";
 import * as fs from "fs";
 import * as path from "path";
 
-// Migration map: old keys → new keys (for backward compatibility)
-const AGENT_NAME_MAP: Record<string, string> = {
-  // Legacy names (backward compatibility)
-  omo: "Sisyphus",
-  "OmO": "Sisyphus",
-  "OmO-Plan": "Planner-Sisyphus",
-  "omo-plan": "Planner-Sisyphus",
-  // Current names
-  sisyphus: "Sisyphus",
-  "planner-sisyphus": "Planner-Sisyphus",
-  build: "build",
-  oracle: "oracle",
-  librarian: "librarian",
-  explore: "explore",
-  "frontend-ui-ux-engineer": "frontend-ui-ux-engineer",
-  "document-writer": "document-writer",
-  "multimodal-looker": "multimodal-looker",
-};
-
-// Migration map: old hook names → new hook names (for backward compatibility)
-const HOOK_NAME_MAP: Record<string, string> = {
-  // Legacy names (backward compatibility)
-  "anthropic-auto-compact": "anthropic-context-window-limit-recovery",
-};
-
-function migrateAgentNames(agents: Record<string, unknown>): { migrated: Record<string, unknown>; changed: boolean } {
-  const migrated: Record<string, unknown> = {};
-  let changed = false;
-
-  for (const [key, value] of Object.entries(agents)) {
-    const newKey = AGENT_NAME_MAP[key.toLowerCase()] ?? AGENT_NAME_MAP[key] ?? key;
-    if (newKey !== key) {
-      changed = true;
-    }
-    migrated[newKey] = value;
-  }
-
-  return { migrated, changed };
-}
-
-function migrateHookNames(hooks: string[]): { migrated: string[]; changed: boolean } {
-  const migrated: string[] = [];
-  let changed = false;
-
-  for (const hook of hooks) {
-    const newHook = HOOK_NAME_MAP[hook] ?? hook;
-    if (newHook !== hook) {
-      changed = true;
-    }
-    migrated.push(newHook);
-  }
-
-  return { migrated, changed };
-}
-
-function migrateConfigFile(configPath: string, rawConfig: Record<string, unknown>): boolean {
-  let needsWrite = false;
-
-  if (rawConfig.agents && typeof rawConfig.agents === "object") {
-    const { migrated, changed } = migrateAgentNames(rawConfig.agents as Record<string, unknown>);
-    if (changed) {
-      rawConfig.agents = migrated;
-      needsWrite = true;
-    }
-  }
-
-  if (rawConfig.omo_agent) {
-    rawConfig.sisyphus_agent = rawConfig.omo_agent;
-    delete rawConfig.omo_agent;
-    needsWrite = true;
-  }
-
-  if (rawConfig.disabled_hooks && Array.isArray(rawConfig.disabled_hooks)) {
-    const { migrated, changed } = migrateHookNames(rawConfig.disabled_hooks as string[]);
-    if (changed) {
-      rawConfig.disabled_hooks = migrated;
-      needsWrite = true;
-    }
-  }
-
-  if (needsWrite) {
-    try {
-      fs.writeFileSync(configPath, JSON.stringify(rawConfig, null, 2) + "\n", "utf-8");
-      log(`Migrated config file: ${configPath}`);
-    } catch (err) {
-      log(`Failed to write migrated config to ${configPath}:`, err);
-    }
-  }
-
-  return needsWrite;
-}
-
 function loadConfigFromPath(configPath: string, ctx: any): OhMyOpenCodeConfig | null {
   try {
     if (fs.existsSync(configPath)) {