WIP: Remove global state from pi-ai OAuth/API key handling

- Remove setApiKey, resolveApiKey, and global apiKeys Map from stream.ts
- Rename getApiKey to getApiKeyFromEnv (only checks env vars)
- Remove OAuth storage layer (storage.ts deleted)
- OAuth login/refresh functions now return credentials instead of saving
- getOAuthApiKey/refreshOAuthToken now take credentials as params
- Add test/oauth.ts helper for ai package tests
- Simplify root npm run check (single biome + tsgo pass)
- Remove redundant check scripts from most packages
- Add web-ui and coding-agent examples to biome/tsgo includes

coding-agent still has compile errors - needs refactoring for new API

packages/coding-agent/examples/sdk/12-full-control.ts

@@ -10,19 +10,19 @@
  */
 
 import { Type } from "@sinclair/typebox";
+import { getAgentDir } from "../../src/config.js";
 import {
-	createAgentSession,
+	type CustomAgentTool,
 	configureOAuthStorage,
+	createAgentSession,
+	createBashTool,
+	createReadTool,
 	defaultGetApiKey,
 	findModel,
+	type HookFactory,
 	SessionManager,
 	SettingsManager,
-	createReadTool,
-	createBashTool,
-	type HookFactory,
-	type CustomAgentTool,
 } from "../../src/index.js";
-import { getAgentDir } from "../../src/config.js";
 
 // Use OAuth from default location
 configureOAuthStorage(getAgentDir());