feat: show golden VM tag in clone list, add console logging, fix ubuntu boot

- Persist golden VM tag to clones/{id}/tag at spawn time
- GET /clones now returns [{id, tag}] objects instead of plain IDs
- Web UI renders tag as a dim label next to each clone entry (clone 3 · default)
- Pre-existing fixes included in this commit:
  - console: tee all PTY output to clones/{id}/console.log for boot capture
  - network: destroy stale tap before recreating to avoid EBUSY errors
  - orchestrator: fix ubuntu systemd boot (custom fc-console.service, fstab,
    mask serial-getty udev dep, longer settle time, correct package list)
  - config: remove quiet/loglevel=0 from default boot args

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

orchestrator/config.go

@@ -34,7 +34,7 @@ func DefaultConfig() Config {
 		GuestPrefix:  envOr("FC_GUEST_PREFIX", "172.30.0"),
 		GuestGW:      envOr("FC_GUEST_GW", "172.30.0.1"),
 		AutoNetConfig: envOr("FC_AUTO_NET_CONFIG", "") == "1",
-		BootArgs:     "console=ttyS0 reboot=k panic=1 pci=off i8042.noaux quiet loglevel=0",
+		BootArgs:     "console=ttyS0 reboot=k panic=1 pci=off i8042.noaux",
 	}
 	c.Kernel = envOr("FC_KERNEL", c.BaseDir+"/vmlinux")
 	c.KernelURL = envOr("FC_KERNEL_URL",