feat(ui): make app header full-width and move Doctor into header controls

- Drop the fixed max-width on .header-container so the header spans the
  viewport while the card grid keeps its own content width
- Keep header icon click targets at 32px at all breakpoints and add
  role/tabindex/aria-label plus Enter/Space activation
- Relocate the Doctor trigger from the page toolbar to the header icon
  group (also available on the statistics page and in the hamburger
  menu), removing the now-unused .doctor-trigger styles

static/css/components/modal/doctor-modal.css

@@ -1,13 +1,3 @@
-.doctor-trigger {
-    min-width: 120px;
-    position: relative;
-    border-color: color-mix(in srgb, var(--lora-accent) 24%, var(--border-color));
-}
-
-.doctor-trigger i {
-    color: var(--lora-accent);
-}
-
 .doctor-status-badge {
     display: inline-flex;
     align-items: center;
@@ -247,15 +237,6 @@
 }
 
 @media (max-width: 760px) {
-    .doctor-trigger {
-        min-width: auto;
-        padding-inline: 10px;
-    }
-
-    .doctor-trigger span:not(.doctor-status-badge) {
-        display: none;
-    }
-
     .doctor-hero,
     .doctor-footer {
         flex-direction: column;