cmd/tsconnect: allow SSH connection timeout to be overridden

5 seconds may not be enough if we're still loading the derp map and
connecting to a slow machine.

Updates #5693

Signed-off-by: Mihai Parparita <mihai@tailscale.com>

cmd/tsconnect/src/lib/ssh.ts

@@ -5,6 +5,8 @@ import { WebLinksAddon } from "xterm-addon-web-links"
 export type SSHSessionDef = {
   username: string
   hostname: string
+  /** Defaults to 5 seconds */
+  timeoutSeconds?: number
 }
 
 export function runSSHSession(
@@ -62,6 +64,7 @@ export function runSSHSession(
       }
       onDone()
     },
+    timeoutSeconds: def.timeoutSeconds,
   })
 
   // Make terminal and SSH session track the size of the containing DOM node.