fix(cv): bind letter proposals to current sources and preserve document choices

JobTrackerApi/Services/CoverLetterDocumentRenderer.cs

@@ -32,7 +32,7 @@ public sealed class CoverLetterDocumentRenderer
         if (list) body.Append("</ul>");
         var contact = string.Join(" · ", new[] { s.SenderEmail, s.SenderPhone, s.SenderLocation }.Where(v => !string.IsNullOrWhiteSpace(v)).Select(E));
         var html = $$"""
-            <!DOCTYPE html><html lang="en"><head><meta charset="utf-8">
+            <!DOCTYPE html><html lang="{{E(s.Language)}}"><head><meta charset="utf-8">
             <meta http-equiv="Content-Security-Policy" content="default-src 'none'; style-src 'unsafe-inline'; script-src 'unsafe-inline'; font-src data:; base-uri 'none'">
             <title>{{E(s.Subject)}} — {{E(s.SenderName)}}</title><style>
             {{CvDocumentFonts.Embed(font)}}