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/package.json

@@ -34,7 +34,6 @@
 		"build:binary": "npm run build && bun build --compile ./dist/cli.js --outfile dist/pi && npm run copy-binary-assets",
 		"copy-assets": "mkdir -p dist/modes/interactive/theme && cp src/modes/interactive/theme/*.json dist/modes/interactive/theme/",
 		"copy-binary-assets": "cp package.json dist/ && cp README.md dist/ && cp CHANGELOG.md dist/ && mkdir -p dist/theme && cp src/modes/interactive/theme/*.json dist/theme/ && cp -r docs dist/ && cp -r examples dist/",
-		"check": "tsgo --noEmit && tsgo -p tsconfig.examples.json",
 		"test": "vitest --run",
 		"prepublishOnly": "npm run clean && npm run build"
 	},