Add XML doc to all service interfaces and implementations (#26)

- Update CLAUDE.md: replace incorrect 'no XML doc on internal code' rule
  with the correct convention (XML doc on all public methods and
  non-trivial private/protected helpers)
- Restore /// <summary> on FileDownloadController private helpers
  (HandleRangeRequest, StreamRangeAsync)
- Add full XML doc to all service contracts:
  ICaptchaVerifier, IEmailSender, ICvMatcherService, IJobTextExtractor,
  IJobTokenService, IDocumentClassifier, IRagService, ITextChunker,
  ITextExtractor, IEmailTemplateService, ITemplateService
- Add /// <summary> and /// <inheritdoc /> to all concrete service classes
  and their methods: RecaptchaVerifier, EmailApiEmailSender,
  SmtpEmailDispatcher, CvMatcherService, JobTextExtractor, JobTokenService,
  RagService, DocumentClassifier, TextChunker, TextExtractor,
  HtmlJobSearcher, CvSearchEmailSender, CvSearchJobTask,
  EmailTemplateService, DbTemplateService

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

Apis/api/Services/EmailApiEmailSender.cs

@@ -9,6 +9,9 @@ using Models.Settings;
 
 namespace Api.Services;
 
+/// <summary>
+/// Implements <see cref="IEmailSender"/> by delegating all email dispatch to the internal email-api service via Refit.
+/// </summary>
 public sealed class EmailApiEmailSender : IEmailSender
 {
     private readonly IEmailApiClient _emailApi;
@@ -34,6 +37,7 @@ public sealed class EmailApiEmailSender : IEmailSender
         _log = log;
     }
 
+    /// <inheritdoc />
     public async Task SendContactAsync(ContactRequest req, CancellationToken ct)
     {
         if (string.IsNullOrWhiteSpace(_contact.ToEmail))
@@ -76,6 +80,7 @@ public sealed class EmailApiEmailSender : IEmailSender
         _log.LogInformation("Contact email sent successfully from {SenderEmail}", req.Email);
     }
 
+    /// <inheritdoc />
     public async Task SendSubscribeAsync(SubscribeRequest req, CancellationToken ct)
     {
         if (string.IsNullOrWhiteSpace(_subscribe.ToEmail))
@@ -108,6 +113,7 @@ public sealed class EmailApiEmailSender : IEmailSender
         _log.LogInformation("Subscription email sent successfully for {Email}", req.Email);
     }
 
+    /// <inheritdoc />
     public async Task SendFileDownloadNotificationAsync(string fileName, string? userIp, CancellationToken ct)
     {
         if (string.IsNullOrWhiteSpace(_fileStorage.ToEmail))
@@ -146,6 +152,7 @@ public sealed class EmailApiEmailSender : IEmailSender
         _log.LogInformation("File download notification sent successfully for {FileName}", fileName);
     }
 
+    /// <inheritdoc />
     public async Task SendMatchAsync(string? explicitTo, string subject, string body, string? attachmentPath, CancellationToken ct)
     {
         var operatorCopy = _emailTemplates.GetOperatorCopy("email.match.subject", "en");
@@ -184,6 +191,7 @@ public sealed class EmailApiEmailSender : IEmailSender
         }
     }
 
+    /// <inheritdoc />
     public string BuildMatchEmailBody(string cvDocumentId, JobMatchResponse result, string? jobLabel, string language, string? jobSearchLink = null, int expiryDays = 7)
     {
         var strengths = result.Strengths?.Count > 0
@@ -221,6 +229,7 @@ public sealed class EmailApiEmailSender : IEmailSender
         return body;
     }
 
+    /// <inheritdoc />
     public string BuildMatchEmailSubject(int score, string? jobLabel, string language) =>
         _emailTemplates.Render("email.match.subject", language,
             ("score", score.ToString()),