Add token expiry, edit notice, log allowlist, local-zone test; merge PLAN.md into SPECS.md

get_logs needs a unit from an allowlist (router-*, kea, unbound, networkd,
nftables, ddclient, acme, sshd, kernel). API tokens are valid for 1, 7, 30
(default) or 90 days, or without limit. The overview and the Changes page
say which token made the unapplied changes.

options.json (router://options) no longer holds the options' source paths:
they differ between builds of a release, so a router rebuilding itself
offline had to build the file and failed (found by the update test).

Web UI: panels flow into columns on wide screens and the width is no longer
capped; on phones the navigation is a menu button; the Advanced page uses
panels; VLAN dropdowns show their chosen names; the duplicate WireGuard
heading is gone.

basic: a subtest for wan -> local rules.

SPECS.md is now the only document (decisions, how each part works, and what
is not done yet); PLAN.md is gone.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AeFqV9dZrK6nipHkPfyM4F

pkgs/router-webui/interfaces.go

@@ -216,3 +216,14 @@ func (s Settings) duplicateName() string {
 	}
 	return ""
 }
+
+// devLabel is how a device is shown in a list: a VLAN with a chosen name as
+// "dmz (lan.1002)", anything else as it is.
+func devLabel(devices []Device, name string) string {
+	for _, d := range devices {
+		if d.Name == name && d.Custom != "" {
+			return d.Custom + " (" + name + ")"
+		}
+	}
+	return name
+}