refactor(types): move shared types from renderer to shared directory

- Move type definitions from src/renderer/src/types/ to src/shared/types/
- Add @shared/* path alias to tsconfig.node.json and tsconfig.web.json
- Update all imports from @renderer/types/* to @shared/types/*
- Update AGENTS.md with new directory structure and path alias

This fixes architecture violation where main/preload processes imported
from renderer directory. Types are now properly shared across all processes.

src/main/kintone-api.ts

@@ -1,6 +1,6 @@
 import { KintoneRestAPIClient } from "@kintone/rest-api-client";
 import type { KintoneRestAPIError } from "@kintone/rest-api-client";
-import type { DomainWithPassword } from "@renderer/types/domain";
+import type { DomainWithPassword } from "@shared/types/domain";
 import type {
   KintoneSpace,
   KintoneApp,
@@ -10,7 +10,7 @@ import type {
   KintoneApiError,
   JSFileConfig,
   CSSFileConfig,
-} from "@renderer/types/kintone";
+} from "@shared/types/kintone";
 
 /**
  * Custom error class for Kintone API errors