Sweep all .cshtml files for encoding corruption; add pre-commit guard

Replace all corruption variants with HTML entities across 226 view files:
- 3-char UTF-8-as-Win1252 sequences (ae-corruption)
- Standalone smart/curly quotes that break C# Razor expressions
- Partially re-corrupted variants where the 3rd byte was normalised to ASCII

tools/Fix-Encoding.ps1: re-runnable sweep; uses [char] code points so the
script itself never contains a literal non-ASCII character; supports -DryRun

.githooks/pre-commit: blocks commits containing the ae-corruption byte
signature (xc3xa2xe2x82xac); git core.hooksPath = .githooks so the
hook is repo-committed and active for all future work on this machine.

Build clean; 225 unit tests pass.

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

src/PowderCoating.Web/Views/Announcements/_AnnouncementForm.cshtml

@@ -15,7 +15,7 @@
     <div class="col-12">
         <label class="form-label fw-medium">Message <span class="text-danger">*</span></label>
         <textarea asp-for="Message" class="form-control" rows="3"
-                  placeholder="The platform will be offline for maintenance on Saturday from 2–4 AM ET." required></textarea>
+                  placeholder="The platform will be offline for maintenance on Saturday from 2&ndash;4 AM ET." required></textarea>
         <span asp-validation-for="Message" class="text-danger small"></span>
     </div>
 
@@ -42,7 +42,7 @@
         <div id="planTargetGroup" style="display:none">
             <label class="form-label fw-medium">Plan</label>
             <select asp-for="TargetPlan" class="form-select">
-                <option value="">— select —</option>
+                <option value="">&mdash; select &mdash;</option>
                 @foreach (var p in planConfigs)
                 {
                     <option value="@p.Plan">@p.DisplayName</option>
@@ -52,7 +52,7 @@
         <div id="companyTargetGroup" style="display:none">
             <label class="form-label fw-medium">Company</label>
             <select asp-for="TargetCompanyId" class="form-select">
-                <option value="">— select —</option>
+                <option value="">&mdash; select &mdash;</option>
                 @foreach (var c in companies)
                 {
                     <option value="@c.Id">@c.CompanyName</option>
@@ -93,7 +93,7 @@
         <label class="form-label fw-medium text-muted">Preview</label>
         <div id="announcementPreview" class="alert mb-0" role="alert">
             <strong id="previewTitle">@Model.Title</strong>
-            <span id="previewMessage"> — @Model.Message</span>
+            <span id="previewMessage"> &mdash; @Model.Message</span>
         </div>
     </div>
 </div>
@@ -113,7 +113,7 @@
         const preview = document.getElementById('announcementPreview');
         preview.className = 'alert mb-0 ' + (typeMap[type] || 'alert-info');
         document.getElementById('previewTitle').textContent = document.getElementById('Title').value || 'Title';
-        document.getElementById('previewMessage').textContent = ' — ' + (document.getElementById('Message').value || 'Message');
+        document.getElementById('previewMessage').textContent = ' &mdash; ' + (document.getElementById('Message').value || 'Message');
     }
     document.getElementById('Type')?.addEventListener('change', updatePreview);
     document.getElementById('Title')?.addEventListener('input', updatePreview);