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/GiftCertificates/Create.cshtml

@@ -87,7 +87,7 @@
                         </div>
                         <div class="col-md-6">
                             <label asp-for="RecipientEmail" class="form-label fw-semibold"></label>
-                            <input asp-for="RecipientEmail" type="email" class="form-control" placeholder="Optional — for emailing the certificate" />
+                            <input asp-for="RecipientEmail" type="email" class="form-control" placeholder="Optional &mdash; for emailing the certificate" />
                         </div>
                     </div>
                 </div>