chore(vendor): import pi 0.85.1

Imported as a linear vendor commit so forge rebases do not replay the upstream root tree.

git-subtree-dir: third_party/pi

git-subtree-split: d981de1229ef899957bbe968bc8dcda02a21f477

third_party/pi/packages/agent/vitest.harness.config.ts

@@ -0,0 +1,34 @@
+import { fileURLToPath } from "node:url";
+import { defineConfig } from "vitest/config";
+
+const telemetrySrcIndex = fileURLToPath(new URL("../telemetry/src/index.ts", import.meta.url));
+const aiSrcIndex = fileURLToPath(new URL("../ai/src/index.ts", import.meta.url));
+const aiSrcCompat = fileURLToPath(new URL("../ai/src/compat.ts", import.meta.url));
+const agentSrcIndex = fileURLToPath(new URL("../agent/src/index.ts", import.meta.url));
+
+export default defineConfig({
+	test: {
+		globals: true,
+		environment: "node",
+		testTimeout: 30000,
+		include: ["test/harness/**/*.test.ts"],
+		coverage: {
+			provider: "v8",
+			all: true,
+			include: ["src/harness/**/*.ts", "src/agent.ts", "src/agent-loop.ts"],
+			exclude: ["src/**/*.d.ts"],
+			reporter: ["text", "html", "lcov"],
+			reportsDirectory: "coverage/harness",
+		},
+	},
+	resolve: {
+		conditions: ["source"],
+		alias: [
+			{ find: /^@earendil-works\/pi-telemetry$/, replacement: telemetrySrcIndex },
+			{ find: /^@earendil-works\/pi-agent-core$/, replacement: agentSrcIndex },
+			{ find: /^@earendil-works\/pi-ai$/, replacement: aiSrcIndex },
+			{ find: /^@earendil-works\/pi-ai\/compat$/, replacement: aiSrcCompat },
+		],
+	},
+	ssr: { resolve: { conditions: ["source"] } },
+});