fix(next): Externalize Pi SDK packages in server runtime

Add @mariozechner/pi-agent-core and @mariozechner/pi-ai to withJunior serverExternalPackages so Next dev does not bundle their dynamic module resolution path.

This avoids MODULE_NOT_FOUND errors from Turbopack while keeping the behavior centralized in the shared helper and covered by next-config tests.

Co-Authored-By: GPT-5 Codex <noreply@openai.com>

Author: dcramer

packages/junior/src/next-config.ts

@@ -103,6 +103,8 @@ function applyJuniorConfig(nextConfig: NextConfig | undefined, options?: JuniorC
       "@vercel/sandbox",
       "bash-tool",
       "just-bash",
+      "@mariozechner/pi-agent-core",
+      "@mariozechner/pi-ai",
       "@chat-adapter/slack",
       "@slack/web-api"
     ])),

packages/junior/tests/next-config.test.ts

@@ -32,6 +32,8 @@ describe("withJunior", () => {
         "@vercel/sandbox",
         "bash-tool",
         "just-bash",
+        "@mariozechner/pi-agent-core",
+        "@mariozechner/pi-ai",
         "@chat-adapter/slack",
         "@slack/web-api"
       ])
@@ -69,6 +71,8 @@ describe("withJunior", () => {
         "@vercel/sandbox",
         "bash-tool",
         "just-bash",
+        "@mariozechner/pi-agent-core",
+        "@mariozechner/pi-ai",
         "@chat-adapter/slack",
         "@slack/web-api"
       ])
@@ -113,6 +117,8 @@ describe("withJunior", () => {
         "@vercel/sandbox",
         "bash-tool",
         "just-bash",
+        "@mariozechner/pi-agent-core",
+        "@mariozechner/pi-ai",
         "@chat-adapter/slack",
         "@slack/web-api",
         "custom-package"