Add UI improvements: date formatting, breadcrumbs, clickable rows, and structured menu

- Format dates as YYYY-MM-DD with full timestamp on hover
- Add breadcrumb navigation with hospital icon (🏥) across all pages
- Restructure main menu with grouped dropdowns:
  * Hardware (Assets, Components)
  * Health (Tickets, Failures, Analytics)
  * Settings (Ingest)
- Make table rows clickable on Dashboard, Assets, and Components pages
- Add new Customers page with list view
- Improve dropdown menu stability with JS hover delay

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

internal/api/ui_index.tmpl

@@ -33,13 +33,13 @@
         <tbody>
           {{range $i, $item := .Assets}}
           {{if lt $i 5}}
-          <tr>
+          <tr class="clickable" onclick="navigateToRow('/ui/assets/{{$item.ID}}')">
             <td><a href="/ui/assets/{{$item.ID}}">{{$item.ID}}</a></td>
             <td>{{$item.Name}}</td>
             <td>{{$item.VendorSerial}}</td>
             <td>{{$item.ProjectID}}</td>
             <td>{{if $item.LocationID}}{{$item.LocationID}}{{else}}—{{end}}</td>
-            <td>{{formatTime $item.CreatedAt}}</td>
+            <td title="{{formatTimeFull $item.CreatedAt}}">{{formatTime $item.CreatedAt}}</td>
           </tr>
           {{end}}
           {{end}}
@@ -67,12 +67,12 @@
         <tbody>
           {{range $i, $item := .Components}}
           {{if lt $i 5}}
-          <tr>
+          <tr class="clickable" onclick="navigateToRow('/ui/components/{{$item.ID}}')">
             <td><a href="/ui/components/{{$item.ID}}">{{$item.ID}}</a></td>
             <td>{{$item.VendorSerial}}</td>
             <td>{{if $item.LotID}}{{$item.LotID}}{{else}}—{{end}}</td>
-            <td>{{formatTimePtr $item.FirstSeenAt}}</td>
-            <td>{{formatTime $item.CreatedAt}}</td>
+            <td title="{{formatTimePtrFull $item.FirstSeenAt}}">{{formatTimePtr $item.FirstSeenAt}}</td>
+            <td title="{{formatTimeFull $item.CreatedAt}}">{{formatTime $item.CreatedAt}}</td>
           </tr>
           {{end}}
           {{end}}