fix: break circular dependency in config error utilities to prevent plugin loader crash

- Created src/shared/config-errors.ts to isolate config error state management
- Removed function re-exports (getConfigLoadErrors, clearConfigLoadErrors) from main index.ts
- Only ConfigLoadError type is re-exported from main module to avoid OpenCode calling it as a plugin
- Updated auto-update-checker hook to import from shared/config-errors instead of main index
- Fixes "TypeError: undefined is not an object" crash when OpenCode iterated through ALL exports and called clearConfigLoadErrors(input) which returned undefined

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

src/shared/config-errors.ts

@@ -0,0 +1,18 @@
+export type ConfigLoadError = {
+  path: string
+  error: string
+}
+
+let configLoadErrors: ConfigLoadError[] = []
+
+export function getConfigLoadErrors(): ConfigLoadError[] {
+  return configLoadErrors
+}
+
+export function clearConfigLoadErrors(): void {
+  configLoadErrors = []
+}
+
+export function addConfigLoadError(error: ConfigLoadError): void {
+  configLoadErrors.push(error)
+}