e2e: extend device_interface_set_unlinked incompatibility range to cover RFC-18 InterfaceV2 format change

Author: ben-malbeclabs

e2e/compatibility_test.go

@@ -124,14 +124,19 @@ var knownIncompatibilities = map[string]knownIncompat{
 	// device interface / link commands: --mtu requirement changed from 2048 to 9000.
 	// Versions before 0.12.0 didn't have these commands; versions 0.12.0–0.15.x send
 	// the old MTU value which the current program rejects.
-	"write/device_interface_create":         {ranges: []versionRange{{from: "0.12.0", before: "0.16.0"}}},
-	"write/device_interface_create_2":       {ranges: []versionRange{{from: "0.12.0", before: "0.16.0"}}},
-	"write/device_interface_create_3":       {ranges: []versionRange{{from: "0.12.0", before: "0.16.0"}}},
-	"write/device_interface_create_4":       {ranges: []versionRange{{from: "0.12.0", before: "0.16.0"}}},
-	"write/device_interface_set_unlinked":   {ranges: []versionRange{{from: "0.12.0", before: "0.16.0"}}},
-	"write/device_interface_set_unlinked_2": {ranges: []versionRange{{from: "0.12.0", before: "0.16.0"}}},
-	"write/device_interface_set_unlinked_3": {ranges: []versionRange{{from: "0.12.0", before: "0.16.0"}}},
-	"write/device_interface_set_unlinked_4": {ranges: []versionRange{{from: "0.12.0", before: "0.16.0"}}},
+	"write/device_interface_create":   {ranges: []versionRange{{from: "0.12.0", before: "0.16.0"}}},
+	"write/device_interface_create_2": {ranges: []versionRange{{from: "0.12.0", before: "0.16.0"}}},
+	"write/device_interface_create_3": {ranges: []versionRange{{from: "0.12.0", before: "0.16.0"}}},
+	"write/device_interface_create_4": {ranges: []versionRange{{from: "0.12.0", before: "0.16.0"}}},
+
+	// RFC-18 added flex_algo_node_segments to InterfaceV2. The set_unlinked step reads
+	// back the device account to find the interface — CLIs that predate this format
+	// (≤0.11.0 and 0.16.0) cannot deserialize the new layout and report "interface not
+	// found". Versions 0.12.0–0.15.x additionally sent the old MTU value (2048 vs 9000).
+	"write/device_interface_set_unlinked":   {ranges: []versionRange{{before: "0.17.0"}}},
+	"write/device_interface_set_unlinked_2": {ranges: []versionRange{{before: "0.17.0"}}},
+	"write/device_interface_set_unlinked_3": {ranges: []versionRange{{before: "0.17.0"}}},
+	"write/device_interface_set_unlinked_4": {ranges: []versionRange{{before: "0.17.0"}}},
 	"write/link_create_wan":                 {ranges: []versionRange{{from: "0.12.0", before: "0.16.0"}}},
 	"write/link_create_dzx":                 {ranges: []versionRange{{from: "0.12.0", before: "0.16.0"}}},
 	"write/link_accept_dzx":                 {ranges: []versionRange{{from: "0.12.0", before: "0.16.0"}}},