refactor(core): split index.ts and config-handler.ts into focused modules

Main entry point:
- create-hooks.ts, create-tools.ts, create-managers.ts
- plugin-interface.ts: plugin interface types
- plugin/ directory: plugin lifecycle modules

Config handler:
- agent-config-handler.ts, command-config-handler.ts
- tool-config-handler.ts, mcp-config-handler.ts
- provider-config-handler.ts, category-config-resolver.ts
- agent-priority-order.ts, prometheus-agent-config-builder.ts
- plugin-components-loader.ts

src/plugin-handlers/command-config-handler.ts

@@ -0,0 +1,62 @@
+import type { OhMyOpenCodeConfig } from "../config";
+import {
+  loadUserCommands,
+  loadProjectCommands,
+  loadOpencodeGlobalCommands,
+  loadOpencodeProjectCommands,
+} from "../features/claude-code-command-loader";
+import { loadBuiltinCommands } from "../features/builtin-commands";
+import {
+  loadUserSkills,
+  loadProjectSkills,
+  loadOpencodeGlobalSkills,
+  loadOpencodeProjectSkills,
+} from "../features/opencode-skill-loader";
+import type { PluginComponents } from "./plugin-components-loader";
+
+export async function applyCommandConfig(params: {
+  config: Record<string, unknown>;
+  pluginConfig: OhMyOpenCodeConfig;
+  pluginComponents: PluginComponents;
+}): Promise<void> {
+  const builtinCommands = loadBuiltinCommands(params.pluginConfig.disabled_commands);
+  const systemCommands = (params.config.command as Record<string, unknown>) ?? {};
+
+  const includeClaudeCommands = params.pluginConfig.claude_code?.commands ?? true;
+  const includeClaudeSkills = params.pluginConfig.claude_code?.skills ?? true;
+
+  const [
+    userCommands,
+    projectCommands,
+    opencodeGlobalCommands,
+    opencodeProjectCommands,
+    userSkills,
+    projectSkills,
+    opencodeGlobalSkills,
+    opencodeProjectSkills,
+  ] = await Promise.all([
+    includeClaudeCommands ? loadUserCommands() : Promise.resolve({}),
+    includeClaudeCommands ? loadProjectCommands() : Promise.resolve({}),
+    loadOpencodeGlobalCommands(),
+    loadOpencodeProjectCommands(),
+    includeClaudeSkills ? loadUserSkills() : Promise.resolve({}),
+    includeClaudeSkills ? loadProjectSkills() : Promise.resolve({}),
+    loadOpencodeGlobalSkills(),
+    loadOpencodeProjectSkills(),
+  ]);
+
+  params.config.command = {
+    ...builtinCommands,
+    ...userCommands,
+    ...userSkills,
+    ...opencodeGlobalCommands,
+    ...opencodeGlobalSkills,
+    ...systemCommands,
+    ...projectCommands,
+    ...projectSkills,
+    ...opencodeProjectCommands,
+    ...opencodeProjectSkills,
+    ...params.pluginComponents.commands,
+    ...params.pluginComponents.skills,
+  };
+}