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/Invoices/Index.cshtml

@@ -85,7 +85,7 @@
                 @if (thisMonthOnly && statusFilter == InvoiceStatus.Paid)
                 {
                     <span class="badge bg-success fs-6 fw-normal">
-                        <i class="bi bi-funnel-fill me-1"></i>Paid — @DateTime.Now.ToString("MMMM yyyy")
+                        <i class="bi bi-funnel-fill me-1"></i>Paid &mdash; @DateTime.Now.ToString("MMMM yyyy")
                     </span>
                 }
                 else if (thisMonthOnly)