fix: interface_name strategy, instance hosts in sftp/scp, alias rewrites

Found by the new Docker test environment against a real NetBox 4.7:

- The interface_name strategy filtered IP addresses with interface_name
  and vminterface_name, which NetBox ignores, so it returned the first
  address of the host instead of the named interface's. Use the real
  filters interface and vminterface; a missing interface (HTTP 400)
  falls through to the next strategy.
- sftp and scp took instance-qualified hosts (prod/web01:/path) for
  local paths, because a "/" comes before the ":". Such arguments are
  remote when the prefix is a configured NetBox instance.
- Shell aliases of instance-qualified hosts ran the shortcut rules on
  "instance/host", so anchored rewrite rules never matched.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/netbox/client_test.go

@@ -235,7 +235,7 @@ func TestGetIPsWithFilter(t *testing.T) {
 	defer srv.Close()
 
 	c := NewClient(srv.URL, "token", 0)
-	ips, err := c.GetIPsWithFilter(context.Background(), "device_id=1&interface_name=mgmt0")
+	ips, err := c.GetIPsWithFilter(context.Background(), "device_id=1&interface=mgmt0")
 	if err != nil {
 		t.Fatalf("GetIPsWithFilter: %v", err)
 	}

internal/netbox/sources_test.go

@@ -78,7 +78,7 @@ func TestMultiSourceSearchAndRouting(t *testing.T) {
 			if err != nil || len(ips) != 1 || ips[0] != tc.ip {
 				t.Fatalf("wrong IP source: %v, %v", ips, err)
 			}
-			ips, err = c.GetIPsWithFilterForHost(ctx, host, "device_id=1&interface_name=mgmt0")
+			ips, err = c.GetIPsWithFilterForHost(ctx, host, "device_id=1&interface=mgmt0")
 			if err != nil || len(ips) != 1 || ips[0] != tc.ip {
 				t.Fatalf("wrong interface source: %v, %v", ips, err)
 			}