fix(agent): decouple agent streams from compat

closes #6851

scripts/check-browser-smoke.mjs

@@ -4,6 +4,7 @@ import { dirname, join, resolve } from "node:path";
 import { build } from "esbuild";
 
 const outputPath = join(tmpdir(), "pi-browser-smoke.js");
+const agentTreeshakeOutputPath = join(tmpdir(), "pi-agent-treeshake-smoke.js");
 const errorLogPath = join(tmpdir(), "pi-browser-smoke-errors.log");
 const generatedCatalogDataDir = join(process.cwd(), "packages/ai/src/providers/data");
 
@@ -23,6 +24,22 @@ const generatedCatalogDataPlugin = {
 	},
 };
 
+function normalizePath(path) {
+	return path.replaceAll("\\", "/");
+}
+
+function findInput(inputs, suffix) {
+	return Object.keys(inputs).find((input) => {
+		const normalized = normalizePath(input);
+		return normalized === suffix || normalized.endsWith(`/${suffix}`);
+	});
+}
+
+function includesNodePackage(inputs, packageName) {
+	const marker = `node_modules/${packageName}/`;
+	return Object.keys(inputs).some((input) => normalizePath(input).includes(marker));
+}
+
 try {
 	await build({
 		entryPoints: ["scripts/browser-smoke-entry.ts"],
@@ -33,6 +50,47 @@ try {
 		outfile: outputPath,
 		plugins: [generatedCatalogDataPlugin],
 	});
+
+	const agentTreeshakeBuild = await build({
+		entryPoints: ["scripts/agent-treeshake-smoke-entry.ts"],
+		bundle: true,
+		platform: "browser",
+		format: "esm",
+		logLevel: "silent",
+		metafile: true,
+		outfile: agentTreeshakeOutputPath,
+		plugins: [generatedCatalogDataPlugin],
+		write: false,
+	});
+	const inputs = agentTreeshakeBuild.metafile.inputs;
+	for (const forbiddenInput of [
+		"packages/ai/src/compat.ts",
+		"packages/ai/src/models.generated.ts",
+		"packages/ai/src/providers/all.ts",
+	]) {
+		const includedInput = findInput(inputs, forbiddenInput);
+		if (includedInput) {
+			throw new Error(`Agent selective-provider bundle unexpectedly includes ${includedInput}`);
+		}
+	}
+
+	const aiSdkPackages = [
+		"@anthropic-ai/sdk",
+		"@aws-sdk/client-bedrock-runtime",
+		"@google/genai",
+		"@mistralai/mistralai",
+		"openai",
+	];
+	const includedAiSdkPackages = aiSdkPackages.filter((packageName) => includesNodePackage(inputs, packageName));
+	if (
+		includedAiSdkPackages.length !== 1 ||
+		includedAiSdkPackages[0] !== "@anthropic-ai/sdk"
+	) {
+		throw new Error(
+			`Agent selective-provider bundle SDKs: expected only @anthropic-ai/sdk, found ${includedAiSdkPackages.join(", ") || "none"}`,
+		);
+	}
+
 	process.exit(0);
 } catch (error) {
 	let detailedErrors = "";