fix: use SDK SessionEvent type for forward compat with copilot-sdk 0.3.0

The auditor's session.on() handler used an inline type annotation
that is incompatible with the SessionEvent discriminated union in
@github/copilot-sdk 0.3.0. Import and use the SDK's SessionEvent
type instead — works with both 0.2.x and 0.3.x.

Signed-off-by: Simon Davies <simongdavies@users.noreply.github.com>

Author: simongdavies

src/plugin-system/auditor.ts

@@ -15,7 +15,11 @@ import { createWriteStream, mkdirSync, type WriteStream } from "node:fs";
 import { createRequire } from "node:module";
 import { join } from "node:path";
 import { tmpdir } from "node:os";
-import { approveAll, type CopilotClient } from "@github/copilot-sdk";
+import {
+  approveAll,
+  type CopilotClient,
+  type SessionEvent,
+} from "@github/copilot-sdk";
 import type {
   PluginManifest,
   AuditResult,
@@ -656,7 +660,7 @@ export async function deepAudit(
       signal?.addEventListener("abort", onAbort, { once: true });
 
       const unsubscribe = auditSession.on(
-        (event: { type: string; data?: Record<string, unknown> }) => {
+        (event: SessionEvent) => {
           // Trace every event type so we can see what's happening
           trace(
             `event: ${event.type} ${JSON.stringify(event.data ?? {}).slice(0, 300)}`,