Give every view a TSIG key that selects it

Each view's match-clients starts with "key jarl-view-NAME" (after
"!key" for the views listed after it), so a query signed with a view's
key lands in that view from any address. The secrets are derived from a
random seed in Jarl's database. The delegation check signs its queries
to this server's own addresses with the key of the zone's view: before,
they got whichever view matched the server's address, usually internal.
jarl view key / GET /views/{id}/key show a key for dig -k (tsig:write,
audited). jarl-view- key names are reserved; the importer drops view
keys from a configuration Jarl wrote.

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

cmd/jarld/admin.go

@@ -302,7 +302,11 @@ func renderCmd() *cobra.Command {
 				return err
 			}
 			paths := render.Paths{ConfigDir: filepath.Join(out, "config"), ZoneDir: filepath.Join(out, "zones"), CacheDir: filepath.Join(out, "cache")}
-			o := render.Render(st, paths, renderExtras(a.cfg))
+			x := renderExtras(a.cfg)
+			if x.ViewKeySeed, err = engine.ViewKeySeed(context.Background(), a.store); err != nil {
+				return err
+			}
+			o := render.Render(st, paths, x)
 			for _, f := range o.Files {
 				if err := os.MkdirAll(filepath.Dir(f.Path), 0o750); err != nil {
 					return err