Reservation lease time; reservations by MAC address or client ID

- A reservation can have its own lease time (--lease-time, the
  reservation dialog), over the subnet's. Schema migration 6.
- A reservation with a MAC address and a client ID matches either one
  (a dual-boot machine sends two client IDs from one MAC); before, it
  was found by MAC and then refused. A lease of the reserved address by
  the client's other identity counts as its own.
- The Leases page shows a client's client ID; reserving a lease uses
  both, or one with --by / the dialog's choice.

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

internal/web/static/assets/pages/reservations.js

@@ -1,7 +1,7 @@
 // Reservations: fixed addresses for clients.
 import { h, mount, table, time, input, modal, errorBox, field, confirmDialog, select, debounce, badge, checkbox } from "../ui.js";
 import { get, change, can } from "../api.js";
-import { optionsEditor, subnetLabel } from "../widgets.js";
+import { optionsEditor, subnetLabel, fmtSeconds, parseSeconds } from "../widgets.js";
 import { onLeave } from "../app.js";
 
 // reservationsTable lists reservations with Edit and Delete.
@@ -9,7 +9,7 @@ export function reservationsTable(rs, done, opts = {}) {
   const write = can("config", true);
   return table([
     { label: "Address", render: (r) => [h("span", { class: "mono" }, r.ip), r.disabled ? [" ", badge("disabled", "off")] : null] },
-    { label: "Client", render: (r) => h("span", { class: "mono" }, r.client_id ? "id " + r.client_id : r.mac) },
+    { label: "Client", render: (r) => h("span", { class: "mono" }, r.mac || "", r.mac && r.client_id ? h("span", { class: "muted small" }, " or ") : "", r.client_id ? "id " + r.client_id : "") },
     { label: "Host name", render: (r) => r.hostname || h("span", { class: "muted" }, "–") },
     opts.subnet ? null : { label: "Subnet", render: (r) => r.subnet_id ? h("a", { href: "#/subnets/" + r.subnet_id }, r.subnet) : "–" },
     { label: "Online", render: (r) => r.lease
@@ -51,7 +51,8 @@ export async function reservationDialog(r, done, preset = {}) {
   const inherited = [...settings.options.filter((o) => !(sub && sub.options.some((x) => x.code === o.code))), ...(sub ? sub.options : [])];
   const ip = input({ value: r ? r.ip : preset.ip || "", placeholder: "10.0.10.20", class: "mono" });
   const mac = input({ value: r ? r.mac || "" : preset.mac || "", placeholder: "aa:bb:cc:dd:ee:ff", class: "mono" });
-  const cid = input({ value: r ? r.client_id || "" : "", placeholder: "only for clients known by a client identifier", class: "mono" });
+  const cid = input({ value: r ? r.client_id || "" : preset.client_id || "", placeholder: "optional: option 61, in hex", class: "mono" });
+  const lease = input({ value: r && r.lease_time ? fmtSeconds(r.lease_time) : "", placeholder: "the subnet's" });
   const host = input({ value: r ? r.hostname : preset.hostname || "", placeholder: "nas" });
   const opts = await optionsEditor(r ? r.options : [], inherited);
   const comment = input({ value: r ? r.comment : "" });
@@ -60,7 +61,8 @@ export async function reservationDialog(r, done, preset = {}) {
   const body = h("div", null, h("div", { class: "form-grid" },
     field("Address", ip, "Its subnet is the one whose network holds it. Inside a pool is fine: nobody else gets it."),
     field("MAC address", mac),
-    field("Client identifier", cid, "Optional: match the client's identifier (option 61, hex) instead of its MAC address."),
+    field("Client identifier", cid, "Optional: the client's identifier (option 61, hex). With a MAC address too, either one gets the client this address (a machine that boots two systems sends different identifiers)."),
+    field("Lease time", lease, "This client's lease time (12h, 7d); empty for the subnet's."),
     field("Host name", host, "Sent to the client."),
     field("Options", opts, "Only for this client; they win over the subnet's."),
     field("Comment", comment),
@@ -69,7 +71,9 @@ export async function reservationDialog(r, done, preset = {}) {
     { label: "Cancel", value: null },
     { label: r ? "Save" : "Add reservation", kind: "primary", onclick: async () => {
       mount(err);
-      const v = { ip: ip.value.trim(), mac: mac.value.trim(), client_id: cid.value.trim(), hostname: host.value.trim(), options: opts.value(), comment: comment.value };
+      const lt = parseSeconds(lease.value);
+      if (lt === null) { mount(err, h("div", { class: "msg err" }, "Lease time: write it as 12h, 7d or 30m")); return false; }
+      const v = { ip: ip.value.trim(), mac: mac.value.trim(), client_id: cid.value.trim(), hostname: host.value.trim(), options: opts.value(), lease_time: lt, comment: comment.value };
       if (r) v.disabled = disabled.input.checked;
       try {
         await change(r ? "PATCH" : "POST", r ? "/reservations/" + r.id : "/reservations", v);