Fix streaming for z-ai in anthropic provider, add preliminary support for tool call streaming. Only reporting argument string deltas, not partial JSON objects

packages/ai/package.json

@@ -13,6 +13,7 @@
 		"clean": "rm -rf dist",
 		"generate-models": "npx tsx scripts/generate-models.ts",
 		"build": "npm run generate-models && tsc -p tsconfig.build.json",
+		"dev": "tsc -p tsconfig.build.json --watch",
 		"check": "biome check --write .",
 		"test": "vitest --run",
 		"prepublishOnly": "npm run clean && npm run build"