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/08-slash-commands.ts

@@ -4,7 +4,7 @@
  * File-based commands that inject content when invoked with /commandname.
  */
 
-import { createAgentSession, discoverSlashCommands, SessionManager, type FileSlashCommand } from "../../src/index.js";
+import { createAgentSession, discoverSlashCommands, type FileSlashCommand, SessionManager } from "../../src/index.js";
 
 // Discover commands from cwd/.pi/commands/ and ~/.pi/agent/commands/
 const discovered = discoverSlashCommands();
@@ -21,12 +21,12 @@ const deployCommand: FileSlashCommand = {
 	content: `# Deploy Instructions
 
 1. Build: npm run build
-2. Test: npm test  
+2. Test: npm test
 3. Deploy: npm run deploy`,
 };
 
 // Use discovered + custom commands
-const { session } = await createAgentSession({
+await createAgentSession({
 	slashCommands: [...discovered, deployCommand],
 	sessionManager: SessionManager.inMemory(),
 });