fix: prevent plugin crash by removing non-function exports from barrel files

BREAKING: OpenCode plugin loader calls all exports as functions.
Exporting non-function values (schemas, constants, types) causes TypeError.

Changes:
- Remove OhMyOpenCodeConfigSchema export from root index.ts
- Replace 'export *' with explicit function exports in hooks/index.ts
- Remove 'export *' from comment-checker/index.ts

src/index.ts

@@ -190,7 +190,6 @@ const OhMyOpenCodePlugin: Plugin = async (ctx) => {
 
 export default OhMyOpenCodePlugin
 
-export { OhMyOpenCodeConfigSchema } from "./config"
 export type {
   OhMyOpenCodeConfig,
   AgentName,