fix(coding): resolve packaged Pi imports from runtime root

resources/pi-agent-server.mjs

@@ -1,5 +1,6 @@
 import { randomUUID } from 'node:crypto';
 import { readFile } from 'node:fs/promises';
+import { findPackageJSON } from 'node:module';
 import path from 'node:path';
 import { pathToFileURL } from 'node:url';
 
@@ -14,12 +15,36 @@ const runtimeRoot = runtimeRootFromArgs(process.argv.slice(2));
 const runtimeModule = (...segments) => pathToFileURL(path.join(runtimeRoot, ...segments)).href;
 const runtimePackageUrl = pathToFileURL(path.join(runtimeRoot, 'package.json')).href;
 
+async function runtimePackageModule(packageName) {
+  const packageJsonPath = findPackageJSON(packageName, runtimePackageUrl);
+  if (!packageJsonPath) throw new Error(`Runtime package is unavailable: ${packageName}`);
+  const packageRoot = path.dirname(packageJsonPath);
+  const packageJson = JSON.parse(await readFile(packageJsonPath, 'utf8'));
+  const rootExport = packageJson.exports?.['.'];
+  const entry = (
+    typeof rootExport === 'string'
+      ? rootExport
+      : rootExport?.import
+  ) ?? packageJson.module ?? packageJson.main;
+  if (typeof entry !== 'string' || !entry.trim()) {
+    throw new Error(`Runtime package import entry is unavailable: ${packageName}`);
+  }
+  const entryPath = path.resolve(packageRoot, entry);
+  const entryRelative = path.relative(packageRoot, entryPath);
+  if (!entryRelative || entryRelative === '..' || entryRelative.startsWith(`..${path.sep}`)
+    || path.isAbsolute(entryRelative)) {
+    throw new Error(`Runtime package import entry escapes its package: ${packageName}`);
+  }
+  return pathToFileURL(entryPath).href;
+}
+
 const outputGuard = await import(runtimeModule('dist', 'core', 'output-guard.js'));
 outputGuard.takeOverStdout();
+const piAiModule = await runtimePackageModule('@earendil-works/pi-ai');
 
 const [pi, piAi, httpDispatcher, jsonEvents, jsonl, themeModule, shellModule] = await Promise.all([
   import(runtimeModule('dist', 'index.js')),
-  import(import.meta.resolve('@earendil-works/pi-ai', runtimePackageUrl)),
+  import(piAiModule),
   import(runtimeModule('dist', 'core', 'http-dispatcher.js')),
   import(runtimeModule('dist', 'modes', 'json-event.js')),
   import(runtimeModule('dist', 'modes', 'rpc', 'jsonl.js')),