fix(marker): enable marker support for docker nodes

Docker's _connect_nio and adapter_update_nio_binding applied packet
filters but never called _ubridge_apply_markers, so markers silently
did nothing on Docker links despite docker being in the allowlist.
Add the missing calls (same pattern as the IOU fix).

Also narrow _MARKER_CAPABLE_TYPES to the four types that actually
implement marker support — vpcs, qemu, docker, iou — removing
dynamips, virtualbox, vmware, and cloud which have no marker pathway
and would silently fail when selected as the capture side.

gns3server/controller/udp_link.py

@@ -26,7 +26,7 @@ from gns3server.utils.packet_filter_validation import validate_bpf_syntax, Filte
 # `mark` filter to).  Mirrors _get_filter_node in link.py, minus "nat"
 # (which has no uBridge).
 _MARKER_CAPABLE_TYPES = frozenset({
-    "vpcs", "qemu", "docker", "iou", "virtualbox", "vmware", "dynamips", "cloud",
+    "vpcs", "qemu", "docker", "iou",
 })