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

modules/settings/default.nix

@@ -91,6 +91,11 @@ let
         inherit (options) router;
       };
       warningsAreErrors = false;
+      # Where the options are declared is the source's store path, which differs
+      # between builds of the same release (an update's test sources, a copy
+      # into the store): without it the file is the same everywhere, so a router
+      # that rebuilds itself offline already has it.
+      transformOptions = opt: opt // { declarations = [ ]; };
     }).optionsJSON
     + "/share/doc/nixos/options.json";