release: 0.6.0: Delivery detail page, DNS badge, machine metrics, wide layout

A page per delivery (`/deliveries/{id}`), reached from the *Details* link on
Added:
  - A page per delivery (`/deliveries/{id}`), reached from the *Details* link on
  - A **DNS** badge in the domain list, one per row, carrying the same
  - Machine metrics on the status page: a **Machine** card reporting the
  - An index of the current page's own sections in the navigation column, for the
Changed:
  - Every panel page is laid out in one column of the same width, so moving
  - The mark's small-size variant — the tab icon and the `SP` initials it
  - The stamp's `SELF-HOSTED SMTP RELAY` line is set at 11.5/0.15 instead of
  - The delivery log lists what identifies a message and nothing else: time,
  - Subjects are decoded for display as well as on the way in, so the rows the
  … (4 more in CHANGELOG)

Full detail: CHANGELOG.md (0.6.0).

docs/architecture.md

@@ -133,9 +133,10 @@ unless noted.
 | `/healthz` | Liveness (no auth) |
 | `/setup/*` | One-time admin bootstrap |
 | `/login`, `/logout` | Session auth |
-| `/status` | Process, cert, socket, PTR checks |
+| `/status` | Process, cert, socket, PTR checks; machine CPU/memory/network |
 | `/domains`, `/domains/*` | Domain and application CRUD, DKIM, L2 limits |
 | `/deliveries` | Send log with filters |
+| `/deliveries/{id}` | One send-log row in full |
 | `/mail-queue` | Postfix queue view |
 | `/system-log` | `mail.log` tail |
 | `/reload` | Reload OpenDKIM + Postfix maps |