Redesign header menu: separate account dropdown from dashboard nav

The profile dropdown was doing three jobs at once (account actions, the
job-seeker panel menu, and the admin panel menu) and a stray inline @if
for the notification badge leaked into the markup as literal text.

- Profile dropdown is now account-only: identity card (avatar + name +
  phone), one role-aware dashboard entry, edit profile, logout. This
  removes the leaked @if and de-clutters the menu.
- Dashboard menu is centralized in _PanelNav and auto-rendered by the
  layout on every logged-in panel page (/Admin, /Me, /Employer,
  /Preferences) instead of being duplicated in the dropdown and pages.
- Drop the now-duplicate manual <partial name="_PanelNav" /> from
  Overview, Ingested, Me/Index, Employer/Index.
- CSS: identity-card (.pd-id) styles + mobile tweaks.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/JobsMedical.Web/wwwroot/css/site.css

@@ -132,6 +132,11 @@ a { color: inherit; text-decoration: none; }
 .profile-dropdown a:hover, .pd-logout:hover { background: var(--primary-soft); color: var(--primary-dark); }
 .profile-dropdown form { margin: 0; }
 .pd-head { padding: 8px 12px; font-weight: 800; color: var(--muted); font-size: 13px; }
+.pd-id { display: flex; align-items: center; gap: 10px; padding: 8px 10px 12px; }
+.pd-id .avatar-img, .pd-id .avatar-fallback { width: 42px; height: 42px; font-size: 17px; }
+.pd-id-text { display: flex; flex-direction: column; min-width: 0; line-height: 1.45; }
+.pd-id-text strong { font-size: 14px; color: var(--ink); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
+.pd-id-text .muted { font-size: 12px; }
 .pd-sep { height: 1px; background: var(--line); margin: 4px 0; }
 .pd-logout { color: var(--danger); }
 
@@ -483,6 +488,7 @@ label { font-size: 13px; }
   .profile-dropdown { position: static; display: block; box-shadow: none; border: none; padding: 0; min-width: 0; }
   .profile-dropdown a, .pd-logout { padding: 12px 6px; font-size: 15px; }
   .pd-head { display: none; }
+  .pd-id { padding: 10px 6px; border-bottom: 1px solid var(--line); margin-bottom: 4px; }
   .pd-sep { display: none; }
 
   .cal { border-spacing: 4px; }