fix-1748-own-resolver-wait: the own resolver's file waits 3 s a try

The resolver file of systemd-resolved (resolvers and kept facts) carries options timeout:3 attempts:2 edns0 in place of timeout:1; manifest test asserts both facts, guard test's literal follows.

Builds: design 50 resolver-wait §1, §4 (and §2 of the main file, line 73)

modules/systemd-resolved/module.json

@@ -52,7 +52,7 @@
   "facts": {
     "kept": {
       "path": "/etc/node-resolver/resolv.conf",
-      "template": "# Managed by the mesh, and written by the module holding this machine's own resolver\n# (module systemd-resolved, novox/hq ADR 0247). On every other machine the module holding\n# the uplink writes this file, listing the mesh's resolvers (ADR 0223); here something\n# requires names routed by domain - a VPN client's domains to its own servers - so the file\n# names this machine's own resolver alone, which sends those domains over the VPN's link and\n# every other name to the mesh's resolvers. One server listed, so one answer per name.\n#\n# Its address on the private network, not loopback: a container copies this file, and\n# this address is one it can reach. Another program writing this file is put back by the\n# module's guard, which keeps what it wrote for whoever handles it on this machine.\n# Replaced on every push; edit nothing here.\n{{$own := \"\"}}{{range .Machines}}{{if eq .Name $.Node}}{{$own = .Address}}{{end}}{{end}}nameserver {{if $own}}{{$own}}{{else}}127.0.0.53{{end}}\noptions timeout:1 attempts:2 edns0\n"
+      "template": "# Managed by the mesh, and written by the module holding this machine's own resolver\n# (module systemd-resolved, novox/hq ADR 0247). On every other machine the module holding\n# the uplink writes this file, listing the mesh's resolvers (ADR 0223); here something\n# requires names routed by domain - a VPN client's domains to its own servers - so the file\n# names this machine's own resolver alone, which sends those domains over the VPN's link and\n# every other name to the mesh's resolvers. One server listed, so one answer per name.\n#\n# Its address on the private network, not loopback: a container copies this file, and\n# this address is one it can reach. Another program writing this file is put back by the\n# module's guard, which keeps what it wrote for whoever handles it on this machine.\n# Replaced on every push; edit nothing here.\n{{$own := \"\"}}{{range .Machines}}{{if eq .Name $.Node}}{{$own = .Address}}{{end}}{{end}}nameserver {{if $own}}{{$own}}{{else}}127.0.0.53{{end}}\noptions timeout:3 attempts:2 edns0\n"
     },
     "resolved": {
       "path": "/etc/systemd/resolved.conf.d/50-mesh.conf",
@@ -60,7 +60,7 @@
     },
     "resolvers": {
       "path": "/etc/resolv.conf",
-      "template": "# Managed by the mesh, and written by the module holding this machine's own resolver\n# (module systemd-resolved, novox/hq ADR 0247). On every other machine the module holding\n# the uplink writes this file, listing the mesh's resolvers (ADR 0223); here something\n# requires names routed by domain - a VPN client's domains to its own servers - so the file\n# names this machine's own resolver alone, which sends those domains over the VPN's link and\n# every other name to the mesh's resolvers. One server listed, so one answer per name.\n#\n# Its address on the private network, not loopback: a container copies this file, and\n# this address is one it can reach. Another program writing this file is put back by the\n# module's guard, which keeps what it wrote for whoever handles it on this machine.\n# Replaced on every push; edit nothing here.\n{{$own := \"\"}}{{range .Machines}}{{if eq .Name $.Node}}{{$own = .Address}}{{end}}{{end}}nameserver {{if $own}}{{$own}}{{else}}127.0.0.53{{end}}\noptions timeout:1 attempts:2 edns0\n"
+      "template": "# Managed by the mesh, and written by the module holding this machine's own resolver\n# (module systemd-resolved, novox/hq ADR 0247). On every other machine the module holding\n# the uplink writes this file, listing the mesh's resolvers (ADR 0223); here something\n# requires names routed by domain - a VPN client's domains to its own servers - so the file\n# names this machine's own resolver alone, which sends those domains over the VPN's link and\n# every other name to the mesh's resolvers. One server listed, so one answer per name.\n#\n# Its address on the private network, not loopback: a container copies this file, and\n# this address is one it can reach. Another program writing this file is put back by the\n# module's guard, which keeps what it wrote for whoever handles it on this machine.\n# Replaced on every push; edit nothing here.\n{{$own := \"\"}}{{range .Machines}}{{if eq .Name $.Node}}{{$own = .Address}}{{end}}{{end}}nameserver {{if $own}}{{$own}}{{else}}127.0.0.53{{end}}\noptions timeout:3 attempts:2 edns0\n"
     },
     "suffix": {
       "path": "/etc/node-resolver/suffix",