release: 1.2.0: Panel 1.2.0-1.2.5: layout, RBAC, tests, GUI and CI fixes

[1.2.0]
The second MINOR after 1.0.0: domain administrators with per-domain scope, a panel visual refresh on the SelfPost palette, and refinements to navigation and the send log. Upgrading runs one SQLite migration (`0005_panel_users`); the single administrator becomes a global user.
Added:
  - panel: **domain-admin role** — global administrators manage panel users and
Fixed:
  - Docker build: `LICENSE` is no longer excluded by `.dockerignore`, so the
  - panel: on signed-in pages with a narrow card (**Settings**, the user form)
Changed:
  - panel: navigation session icons are distinct — **Settings** uses a gear,
  - panel: `/` redirects domain administrators to `/domains`; global users still
  - panel: **Sign out** in the navigation column uses the same type size and
  - panel: **visual style** brought in line with the SelfPost mark — brick accent
  - panel: the send log's **status is a badge**, in the same ok/warn/error/unknown
  … (1 more in CHANGELOG)
[1.2.1]
Panel refinements after 1.2.0: navigation icons, status-badge centreing, drill-down back-link placement, and safeguards for the sole global administrator. Upgrading is a tag bump; no migration.
Fixed:
  - panel: status badge text sat low in the box (and below the heading or label
  - panel: the **Users** navigation icon was two full silhouettes with staggered
  - panel: the **Settings** navigation icon was a sun-with-rays (circle plus
  - panel: the user create/edit form placed «Back to users» at the bottom of the
Changed:
  - panel: the user edit form disables role change and delete for the only global
  - panel: the user create/edit form hides **Assigned domains** when the role is
  - panel: **Settings** shows panel credentials and DMARC aggregate reports side
[1.2.2]
Status page layout after 1.2.1: paired cards in a wide column, denser machine and check copy, and a user-form checkbox fix. Upgrading is a tag bump; no migration.
Changed:
  - panel: **Status** is wide again so paired cards fill the column. Layout:
Fixed:
  - panel: cards inside `.split` used `margin: 0 auto`, which in a CSS grid
  - panel: on the user create/edit form, **Assigned domains** checkboxes stacked
[1.2.3]
Domain detail layout and panel polish after 1.2.2. Upgrading is a tag bump; no migration.
Changed:
  - panel: the domain detail page is wide with paired cards (DKIM+SPF ‖ DMARC;
  - panel: Domains list — **Add domain** sits beside the domain field; the
  - panel: page URLs, browser titles, and headings are aligned — **Settings** is
Fixed:
  - image: `mail.log` rotation no longer silently stops when the build context
[1.2.4]
Level-2 rate-limit semantics inverted after 1.2.3, plus a small DNS field height fix. Upgrading is a tag bump; no migration.
Changed:
  - rate limiting (level 2): domain ceilings apply to every client IP (no IP
Fixed:
  - panel: on the domain DNS status grid, the Type (TXT) field height matches
[1.2.5]
Rate-limit form polish after 1.2.4. Upgrading is a tag bump; no migration.
Changed:
  - panel: rate-limit forms refined — level-1 backstop as muted copy on the

Squashed CHANGELOG sections: [1.2.0], [1.2.1], [1.2.2], [1.2.3], [1.2.4], [1.2.5].

Full detail: CHANGELOG.md (1.2.0, 1.2.1, 1.2.2, 1.2.3, 1.2.4, 1.2.5).

internal/web/view/templates/delivery.html

@@ -18,7 +18,7 @@
   <span class="st st-{{.Level}}">{{.Row.Status}}</span>
 </p>
 
-<a class="back" href="{{.BackURL}}">&larr; Back to deliveries</a>
+{{template "back_link" (back .BackURL "Back to deliveries")}}
 
 {{/* The two columns: what was recorded on the left, in what order it happened
      on the right. They are a pair — the facts are only worth reading against