Update email templates to HTML format and fix EmailApiEmailSender

- Convert email.match.body, email.match.job-search-footer, email.search-results.body, and email.search-results.empty templates from plain text to proper HTML format in InitialSchema migration
- Update EmailApiEmailSender.BuildMatchEmailBody() to work with HTML templates instead of plain text
- Add WebUtility.HtmlEncode() for security when inserting dynamic content (summary)
- Templates now use semantic HTML tags (table, h2, h3, ul, li, p, div, hr, a) instead of plain text with newlines
- All 32 email template variants (16 keys × 2 languages) and 8 html.job-search.* templates seeded via migration

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

Apis/api/Services/EmailApiEmailSender.cs

@@ -6,6 +6,7 @@ using EmailApi.Models.Requests;
 using Microsoft.Extensions.Options;
 using Models.Requests;
 using Models.Settings;
+using System.Net;
 
 namespace Api.Services;
 
@@ -194,31 +195,35 @@ public sealed class EmailApiEmailSender : IEmailSender
     /// <inheritdoc />
     public string BuildMatchEmailBody(string cvDocumentId, JobMatchResponse result, string? jobLabel, string language, string? jobSearchLink = null, int expiryDays = 7)
     {
+        // Build HTML lists for strengths, gaps, and recommendations
         var strengths = result.Strengths?.Count > 0
-            ? "<ul style=\"color:#495057;padding-left:20px;line-height:1.8\">" +
+            ? "<ul style=\"color:#495057;padding-left:20px;line-height:1.8;margin:0\">" +
               string.Join("", result.Strengths.Select(s => $"<li>{s}</li>")) + "</ul>"
-            : "<p style=\"color:#6c757d\">—</p>";
+            : "<p style=\"color:#6c757d;margin:0\">—</p>";
 
         var gaps = result.Gaps?.Count > 0
-            ? "<ul style=\"color:#495057;padding-left:20px;line-height:1.8\">" +
+            ? "<ul style=\"color:#495057;padding-left:20px;line-height:1.8;margin:0\">" +
               string.Join("", result.Gaps.Select(g => $"<li>{g}</li>")) + "</ul>"
-            : "<p style=\"color:#6c757d\">—</p>";
+            : "<p style=\"color:#6c757d;margin:0\">—</p>";
 
         var recommendations = result.Recommendations?.Count > 0
-            ? "<ul style=\"color:#495057;padding-left:20px;line-height:1.8\">" +
+            ? "<ul style=\"color:#495057;padding-left:20px;line-height:1.8;margin:0\">" +
               string.Join("", result.Recommendations.Select(r => $"<li>{r}</li>")) + "</ul>"
-            : "<p style=\"color:#6c757d\">—</p>";
+            : "<p style=\"color:#6c757d;margin:0\">—</p>";
 
+        // Render the HTML template with substituted values
+        // email.match.body is now stored as HTML in the database
         var body = _emailTemplates.Render("email.match.body", language,
             ("cvDocumentId", cvDocumentId),
             ("jobLabel", jobLabel ?? "N/A"),
             ("jobUrl", result.JobUrl ?? "N/A"),
             ("score", result.Score.ToString()),
-            ("summary", result.Summary ?? string.Empty),
+            ("summary", WebUtility.HtmlEncode(result.Summary ?? string.Empty)),
             ("strengths", strengths),
             ("gaps", gaps),
             ("recommendations", recommendations));
 
+        // Append the job search footer if link is provided
         if (!string.IsNullOrWhiteSpace(jobSearchLink))
         {
             body += _emailTemplates.Render("email.match.job-search-footer", language,