fix: persist role field in metadata, isolate role test from name fallback

Bugbot caught two real issues:
- writeMetadata() and readMetadata() never serialized the role field,
  so role=orchestrator was silently dropped on disk
- The role-based test used "app-orchestrator" as session name, so the
  name fallback caught it — role check was never actually exercised

Fix: add role to metadata read/write, rename test session to "app-99"
so only the role metadata path can protect it.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

packages/core/src/__tests__/session-manager.test.ts

@@ -759,8 +759,9 @@ describe("cleanup", () => {
       }),
     };
 
-    // Session with role=orchestrator but a non-standard name
-    writeMetadata(sessionsDir, "app-orchestrator", {
+    // Session with role=orchestrator but a name that does NOT end in "-orchestrator"
+    // so only the role metadata check can protect it (not the name fallback)
+    writeMetadata(sessionsDir, "app-99", {
       worktree: "/tmp",
       branch: "main",
       status: "working",
@@ -773,7 +774,7 @@ describe("cleanup", () => {
     const result = await sm.cleanup();
 
     expect(result.killed).toHaveLength(0);
-    expect(result.skipped).toContain("app-orchestrator");
+    expect(result.skipped).toContain("app-99");
   });
 
   it("skips orchestrator sessions by name fallback (no role metadata)", async () => {

packages/core/src/metadata.ts

@@ -99,6 +99,7 @@ export function readMetadata(dataDir: string, sessionId: SessionId): SessionMeta
     project: raw["project"],
     createdAt: raw["createdAt"],
     runtimeHandle: raw["runtimeHandle"],
+    role: raw["role"],
     dashboardPort: raw["dashboardPort"] ? Number(raw["dashboardPort"]) : undefined,
     terminalWsPort: raw["terminalWsPort"] ? Number(raw["terminalWsPort"]) : undefined,
     directTerminalWsPort: raw["directTerminalWsPort"] ? Number(raw["directTerminalWsPort"]) : undefined,
@@ -141,6 +142,7 @@ export function writeMetadata(
   if (metadata.project) data["project"] = metadata.project;
   if (metadata.createdAt) data["createdAt"] = metadata.createdAt;
   if (metadata.runtimeHandle) data["runtimeHandle"] = metadata.runtimeHandle;
+  if (metadata.role) data["role"] = metadata.role;
   if (metadata.dashboardPort !== undefined)
     data["dashboardPort"] = String(metadata.dashboardPort);
   if (metadata.terminalWsPort !== undefined)