panel-redesign: the queue in the new shell; the old design is removed

Stage 2, steps 7 and 8 in one commit: the static guard fails as soon as
the ratchet holds no page while legacy.css still exists, and the tests
of the old layout need it while that layout exists - the two steps do
not split into states that pass on their own. Written by Sonnet,
reviewed by Opus.

The queue
  - out-queue, named after its mockup: today's content - the listing of
    postqueue -p in a log pane, polled as before (GET
    /outbound/queue/fragment) - and the "How retries work" facts. The
    mockup's table of messages is the roadmap's queue-as-a-table; the
    outline guard exempts this page for exactly that reason. Routes and
    the global-only check are unchanged; the page has no actions and
    never had.
  - Inbound has no Queue entry and no route serves one.

The old design is gone
  - Deleted: layout_legacy.html, legacy.css, logo-compact.svg,
    mail_queue.html, mail_queue_body.html.
  - view.go has one path: every page is layout.html + components.html +
    its own files; kitPages, kitFragments, the map-data branch of Render,
    the dict and back template functions and metaOf's map branch are
    removed. handlers: pageBase removed.
  - legacy_pages.txt holds its header and no entry.
  - panel.js: the old copy handler (button.copy in .code-row) is
    removed. A show-when rule now applies to every element it matches,
    and hiding adds Bulma's is-hidden beside the hidden attribute - a
    .box or a grid row has a display of its own and stayed visible.
  - The user form hides both domain lists again when the role is Global
    (Box.DomainPick, an attribute; data-global-role on the select).
  - Tests of the old layout are deleted; what they asserted about the
    shell (version only signed in, the menu follows the user's reach,
    Inbound only with the feature, Help present, the current entry
    marked) is asserted on the kit pages, two tests added for it.

For the owner: is-hidden is a Bulma class outside the subset of
check.py. No template writes it - the script sets it at run time to
hide a block - so no guard sees it; say if it should be on the list.

Evidence
  - docs/assets/panel-redesign/evidence/out-queue.png: 1440 px wide,
    headless Edge, the real template served locally with its fixture -
    NOT from the container (no Docker on this machine).
  - panel/audit.js on out-queue, user and backup at 1440 and 1280:
    366 texts checked, problems: [].
  - In a browser against the local fixture server: the encryption
    fields of Backup, the manual / auto limit fields and the custom
    report address of Domain settings show and hide with their control;
    all 28 fixture pages answer 200 with panel.css, /static/legacy.css
    answers 404.
  - Not exercised: polling against a real postqueue (none on Windows).
  - go test -count=1 ./internal/web/... ./cmd/panel
      ok  internal/web
      ok  internal/web/auth
      ok  internal/web/handlers
      ok  internal/web/validate
      ok  internal/web/view
      ok  cmd/panel

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

internal/web/view/outbound_queue_test.go

@@ -0,0 +1,60 @@
+package view
+
+import (
+	"strings"
+	"testing"
+)
+
+// ---- Outbound queue
+
+// The page prints postqueue's listing as it is and polls from its box; the
+// retry policy sits under it, outside the poll.
+func TestOutQueueShowsTheListingAndPollsItsBox(t *testing.T) {
+	out := renderSignedIn(t, "out-queue", outQueueFixture())
+	pageHas(t, "Outbound queue", out,
+		`<h1 class="title is-3">Outbound queue</h1>`, `<h2>Waiting</h2>`,
+		`id="out-queue" data-poll aria-live="polite" hx-get="/outbound/queue/fragment" hx-trigger="load" hx-swap="outerHTML"`,
+		`class="sp-log"`, `-Queue ID-  --Size-- `, `4XcB7k2Jm9z1     3174 Sun Sep 21 13:58:07  alerts@example.org`,
+		`-- 3 Kbytes in 1 Request.`,
+		`aria-current="page"><i class="ti ti-stack-2"></i>Queue</a>`,
+	)
+	// What Postfix printed is escaped, not interpreted.
+	pageHas(t, "Outbound queue", out, `(host mx1.example.org[192.0.2.10] said: 451 4.7.1 Greylisted`)
+	pageLacks(t, "Outbound queue", out, "<table", "Queue is empty.")
+
+	frag := renderFragment(t, "out_queue_body", outQueueFixture())
+	if !strings.HasPrefix(frag, `<div class="box" id="out-queue" data-poll`) || strings.Contains(frag, "sp-head") || strings.Contains(frag, "How retries work") {
+		t.Errorf("the fragment is not the polled box alone:\n%.200s", frag)
+	}
+	if strings.Count(out, `class="sp-log"`) != 1 || strings.Count(frag, `class="sp-log"`) != 1 {
+		t.Error("the page and its fragment should each carry the listing once")
+	}
+}
+
+// The policy is the page's, wherever it was read from: its facts, and a head
+// that says so when they are the compiled-in defaults.
+func TestOutQueueStatesTheRetryPolicy(t *testing.T) {
+	out := renderSignedIn(t, "out-queue", NewOutQueue(admin(), "", "").WithRetryPolicy("10 minutes", "about 1 hour 7 minutes", "2 days", false))
+	pageHas(t, "Outbound queue", out,
+		`<h2>How retries work</h2>`, `This Postfix&#39;s policy, read at panel start`,
+		`<dd class="sp-big">10 minutes</dd>`, `<dd class="sp-big">doubling</dd>`, `capped at about 1 hour 7 minutes`,
+		`<dd class="sp-big">2 days</dd>`, `<dd class="sp-big">bounced</dd>`, `no attempt counter, only time`,
+	)
+	pageLacks(t, "Outbound queue", out, "Compiled-in defaults")
+
+	out = renderSignedIn(t, "out-queue", NewOutQueue(admin(), "", "").WithRetryPolicy("5 minutes", "about 1 hour 7 minutes", "5 days", true))
+	pageHas(t, "Outbound queue", out, "Compiled-in defaults: the Postfix configuration could not be read")
+	pageLacks(t, "Outbound queue", out, "read at panel start")
+}
+
+// With nothing to list the box says why instead: the queue holds nothing, or
+// it could not be read — and never both.
+func TestOutQueueSaysWhyItHasNoListing(t *testing.T) {
+	out := renderSignedIn(t, "out-queue", NewOutQueue(admin(), "", ""))
+	pageHas(t, "empty queue", out, `class="sp-empty"`, "Queue is empty.")
+	pageLacks(t, "empty queue", out, `class="sp-log"`, "Could not read")
+
+	out = renderSignedIn(t, "out-queue", NewOutQueue(admin(), "ignored", "Could not read the mail queue."))
+	pageHas(t, "unreadable queue", out, `class="sp-empty"`, "Could not read the mail queue.")
+	pageLacks(t, "unreadable queue", out, `class="sp-log"`, "Queue is empty.", "ignored")
+}