fix(cv-search-job): separate keyword badges with whitespace in results email

string.Join("") produced no whitespace between inline-block spans,
causing keywords to visually merge in email clients that collapse margins.
Switched to string.Join(" ") and zeroed left margin on each badge so
they wrap cleanly without a gap on the first item.

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

Jobs/cv-search-job/Services/CvSearchEmailSender.cs

@@ -123,8 +123,8 @@ public sealed class CvSearchEmailSender
     private static string BuildScanSummary(IReadOnlyList<string> keywords, IReadOnlyList<string> providerNames)
     {
         var keywordsHtml = keywords.Count > 0
-            ? string.Join("", keywords.Select(k =>
-                $"<span style=\"display:inline-block;background:#e9ecef;border-radius:4px;padding:2px 8px;margin:2px;font-size:12px\">{k}</span>"))
+            ? string.Join(" ", keywords.Select(k =>
+                $"<span style=\"display:inline-block;background:#e9ecef;border-radius:4px;padding:2px 8px;margin:2px 2px 2px 0;font-size:12px\">{k}</span>"))
             : "<span style=\"color:#6c757d;font-size:12px;font-style:italic\">none detected</span>";
 
         var providersText = providerNames.Count > 0