Initial implementation of inventree

A small IT asset inventory system built around a nested folder tree,
matching the project brief: Go + html/template + Bootstrap 5 + vanilla JS,
SQLite storage (WAL, FKs, migrations), embedded templates/static assets,
single compiled binary.

- AJAX-driven inventory tree: lazy-loaded folder expansion with per-user
  persisted expand state, drag-and-drop move for folders/assets, safe
  delete-with-relocate-or-cascade confirmation, search with breadcrumbs.
- Assets: CRUD, duplicate, move, auto-generated IT-000001-style IDs,
  CSV import (with optional folder auto-create) and export.
- Admin-defined item types with custom fields (text/long_text/number/date/
  boolean/dropdown/url/ip_address).
- Configurable statuses, session-based auth (bcrypt, secure cookies),
  admin/user roles, user management.
- CLI: serve, version, database migrate, database backup; /healthz;
  graceful shutdown; Dockerfile/docker-compose/systemd unit; Go test suite.

web/templates/partials/panel_root.html

@@ -0,0 +1,109 @@
+{{define "panel_root"}}
+<div class="panel-content p-3">
+  <nav aria-label="breadcrumb">
+    <ol class="breadcrumb mb-2">
+      <li class="breadcrumb-item active" aria-current="page">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>
+
+  <div class="d-flex align-items-center mb-2">
+    <h6 class="mb-0">Top-Level Folders</h6>
+    <div class="ms-auto d-flex gap-2">
+      <a class="btn btn-sm btn-outline-secondary" href="/export/assets.csv"><i class="bi bi-download"></i> Export CSV</a>
+      <button class="btn btn-sm btn-outline-secondary admin-only" data-bs-toggle="modal" data-bs-target="#importModal"><i class="bi bi-upload"></i> Import CSV</button>
+      <button class="btn btn-sm btn-primary admin-only" id="btn-new-folder-root"><i class="bi bi-folder-plus"></i> New Folder</button>
+    </div>
+  </div>
+
+  {{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. {{if true}}<span class="admin-only">Create one to start organizing your inventory.</span>{{end}}</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>
+{{end}}