fix: fail open when whoami resolves without a role

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01L99mAR4LitqTcYY1Kn1ATH

frontend/src/lib/components/copilot/chat/global/sessionAccess.test.ts

@@ -83,4 +83,10 @@ describe('resolveSessionAccess', () => {
 		expect(access.capabilities.has('write_draft')).toBe(true)
 		expect(access.capabilities.has('deploy')).toBe(true)
 	})
+
+	it('fails open on a body that resolves without a role, rather than throwing', async () => {
+		whoami.mockResolvedValueOnce(undefined)
+		const access = await resolveSessionAccess('ws')
+		expect(access.capabilities.has('write_draft')).toBe(true)
+	})
 })

frontend/src/lib/components/copilot/chat/global/sessionAccess.ts

@@ -42,10 +42,14 @@ export function hasCapabilities(
 }
 
 export async function resolveSessionAccess(workspace: string): Promise<SessionAccess> {
-	let me: User
+	let me: User | undefined
 	try {
 		me = await UserService.whoami({ workspace })
-	} catch {
+	} catch {}
+	// Checked rather than trusted: a body that arrives malformed resolves without
+	// throwing, and reading a capability off it would surface as a TypeError thrown
+	// out of the send rather than as the fail-open this whole path promises.
+	if (!me) {
 		return fullSessionAccess(workspace)
 	}