Hide churned trial accounts from company/health screens by default

- Companies list and Company Health now hide Expired/Canceled accounts
  whose subscription ended 14+ days ago; show/hide toggle via banner
- KPI cards on Company Health exclude churned tenants when hidden
- showChurned param threads through sort, pagination, search, and filter forms
- Powder catalog: fix missing UnitPrice on user-contributed entries;
  add back-sync to fill catalog gaps on existing matches; wire
  AiAugmentFromUrl and manual inventory Create into catalog contribute path

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/PowderCoating.Web/Views/CompanyHealth/Index.cshtml

@@ -4,6 +4,9 @@
 @{
     ViewData["Title"] = "Company Health";
 
+    var showChurned  = (bool)(ViewBag.ShowChurned ?? false);
+    var churnedCount = (int)(ViewBag.ChurnedCount ?? 0);
+
     string RiskBadge(ChurnRisk r) => r switch {
         ChurnRisk.Healthy        => "bg-success",
         ChurnRisk.AtRisk         => "bg-warning text-dark",
@@ -73,6 +76,26 @@
         </div>
     </div>
 
+    @* Churned account visibility banner *@
+    @if (churnedCount > 0 && !showChurned)
+    {
+        <div class="alert alert-secondary alert-permanent d-flex align-items-center gap-2 mb-3 py-2">
+            <i class="bi bi-eye-slash text-muted"></i>
+            <span class="small"><strong>@churnedCount</strong> churned @(churnedCount == 1 ? "account" : "accounts") (expired or canceled 14+ days ago) hidden from scores and totals.</span>
+            <a href="@Url.Action("Index", new { risk = ViewBag.Risk, search = ViewBag.Search, configIssuesOnly = ViewBag.ConfigIssuesOnly, showChurned = true })"
+               class="btn btn-sm btn-outline-secondary ms-auto py-0">Show churned</a>
+        </div>
+    }
+    else if (showChurned && churnedCount > 0)
+    {
+        <div class="alert alert-warning alert-permanent d-flex align-items-center gap-2 mb-3 py-2">
+            <i class="bi bi-eye text-warning"></i>
+            <span class="small">Showing all accounts including <strong>@churnedCount</strong> churned.</span>
+            <a href="@Url.Action("Index", new { risk = ViewBag.Risk, search = ViewBag.Search, configIssuesOnly = ViewBag.ConfigIssuesOnly, showChurned = false })"
+               class="btn btn-sm btn-outline-secondary ms-auto py-0">Hide churned</a>
+        </div>
+    }
+
     @* Summary stat cards *@
     <div class="row g-3 mb-3">
         <div class="col-6 col-lg-3">
@@ -193,6 +216,7 @@
                         <label class="form-check-label small" for="configOnly">Config issues only</label>
                     </div>
                 </div>
+                <input type="hidden" name="showChurned" value="@showChurned.ToString().ToLower()" />
                 <div class="col-auto">
                     <button class="btn btn-sm btn-primary">Filter</button>
                     <a asp-action="Index" class="btn btn-sm btn-outline-secondary ms-1">Clear</a>