refactor: update plugin handlers and shared utils

Minor updates to config handler, plugin detector, index entry, and builtin command templates.

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

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

src/index.ts

@@ -288,7 +288,7 @@ const OhMyOpenCodePlugin: Plugin = async (ctx) => {
     : null;
 
   const configHandler = createConfigHandler({
-    ctx,
+    ctx: { directory: ctx.directory, client: ctx.client },
     pluginConfig,
     modelCacheState,
   });