Blank root panel, asset form as a modal, and a dedicated Statuses page

- Main panel is now blank at the top level ("Select a folder or asset
  from the tree") instead of showing a dashboard - browsing happens in
  the tree, the panel only shows something once you click into it.
  Removed the now-dead DashboardStats/Stats() machinery it depended on.
- Add/Edit Asset no longer takes over the main panel; it opens in
  #assetModal instead; asset_form.html was trimmed down to just the form
  (no more breadcrumb/panel wrapper) since the modal chrome provides the
  title and footer buttons now. The dynamic item-type-fields and submit
  listeners moved from #main-panel's delegation to the modal element's.
- Statuses split out of the General settings page into its own
  /settings/statuses page and sub-nav entry, alongside General, Item
  Types, and Users.

web/templates/partials/panel_root.html

@@ -1,102 +1,5 @@
 {{define "panel_root"}}
-<div class="panel-content p-3" data-panel-type="root">
-  <nav aria-label="breadcrumb">
-    <ol class="breadcrumb mb-2">
-      <li class="breadcrumb-item active" aria-current="page" data-type="root">Inventory</li>
-    </ol>
-  </nav>
-
-  <div class="row g-2 mb-3">
-    <div class="col-6 col-md-2">
-      <div class="card stat-card">
-        <div class="card-body py-2">
-          <div class="stat-value">{{.Stats.Total}}</div>
-          <div class="stat-label">Total Assets</div>
-        </div>
-      </div>
-    </div>
-    {{range .Stats.ByStatus}}
-    <div class="col-6 col-md-2">
-      <div class="card stat-card">
-        <div class="card-body py-2">
-          <div class="stat-value">{{.Count}}</div>
-          <div class="stat-label"><span class="badge text-bg-{{.Color}}">{{.Name}}</span></div>
-        </div>
-      </div>
-    </div>
-    {{end}}
-  </div>
-
-  <div class="row g-3 mb-3">
-    <div class="col-md-6">
-      <div class="card h-100">
-        <div class="card-header py-2 fw-semibold">Assets by Type</div>
-        <ul class="list-group list-group-flush">
-          {{range .Stats.ByType}}
-          <li class="list-group-item d-flex justify-content-between align-items-center py-1">
-            <span><i class="bi {{iconOr .Icon "bi-box-seam"}} me-2"></i>{{.Name}}</span>
-            <span class="badge text-bg-secondary rounded-pill">{{.Count}}</span>
-          </li>
-          {{else}}
-          <li class="list-group-item text-body-secondary py-2">No assets yet.</li>
-          {{end}}
-        </ul>
-      </div>
-    </div>
-    <div class="col-md-6">
-      <div class="card h-100">
-        <div class="card-header py-2 fw-semibold">Recently Added</div>
-        <ul class="list-group list-group-flush">
-          {{range .Stats.RecentlyAdded}}
-          <li class="list-group-item py-1">
-            <a href="#" class="asset-link text-decoration-none" data-id="{{.ID}}">
-              <i class="bi {{iconOr .ItemTypeIcon "bi-box-seam"}} me-2"></i>{{.Name}}
-              <span class="text-body-secondary small">{{.AssetTag}}</span>
-            </a>
-          </li>
-          {{else}}
-          <li class="list-group-item text-body-secondary py-2">No assets yet.</li>
-          {{end}}
-        </ul>
-      </div>
-    </div>
-  </div>
-
-  <h6 class="mb-2">Top-Level Folders</h6>
-
-  {{if .Folders}}
-  <div class="list-group mb-3">
-    {{range .Folders}}
-    <a href="#" class="list-group-item list-group-item-action folder-link d-flex align-items-center" data-id="{{.ID}}">
-      <i class="bi {{iconOr .Icon "bi-folder-fill"}} text-warning-emphasis me-2"></i>
-      {{.Name}}
-      <span class="text-body-secondary small ms-2">{{if .Description}}{{.Description}}{{end}}</span>
-      <span class="ms-auto text-body-secondary small">{{.FolderCount}} folder(s), {{.AssetCount}} asset(s)</span>
-    </a>
-    {{end}}
-  </div>
-  {{else}}
-  <p class="text-body-secondary">No folders yet. <span class="admin-only">Right-click here (or the tree) to create one.</span></p>
-  {{end}}
-
-  {{if .UnfiledAssets}}
-  <h6 class="mb-2">Unfiled Assets</h6>
-  <div class="table-responsive">
-    <table class="table table-sm table-hover asset-table">
-      <thead><tr><th>Asset ID</th><th>Name</th><th>Type</th><th>Status</th><th>Assigned</th></tr></thead>
-      <tbody>
-        {{range .UnfiledAssets}}
-        <tr class="asset-row" data-id="{{.ID}}">
-          <td>{{.AssetTag}}</td>
-          <td><i class="bi {{iconOr .ItemTypeIcon "bi-box-seam"}} me-1"></i>{{.Name}}</td>
-          <td>{{.ItemTypeName}}</td>
-          <td><span class="badge text-bg-{{.StatusColor}}">{{.StatusName}}</span></td>
-          <td>{{if .AssignedUsername}}{{.AssignedUsername}}{{else}}<span class="text-body-secondary">&mdash;</span>{{end}}</td>
-        </tr>
-        {{end}}
-      </tbody>
-    </table>
-  </div>
-  {{end}}
+<div class="panel-content panel-blank p-3 h-100 d-flex align-items-center justify-content-center" data-panel-type="root">
+  <p class="text-body-secondary mb-0">Select a folder or asset from the tree.</p>
 </div>
 {{end}}