Fix language consistency in job search and match emails

1. Pass session.Language to MatchJobRequest in cv-search-job so the LLM
   uses the correct language-specific prompt for job titles and summaries.

2. Replace hardcoded "Manual job description" with a template-driven label
   (email.match.manual-job-label) seeded in English and Romanian, so the
   match email subject and Job row reflect the user's language.

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

Apis/api/Services/Contracts/IEmailSender.cs

@@ -61,5 +61,11 @@ namespace Api.Services.Contracts
         /// <param name="expiryDays">Number of days until the job-search link expires (shown in the footer copy).</param>
         /// <returns>Rendered HTML body string.</returns>
         string BuildMatchEmailBody(string cvDocumentId, JobMatchResponse result, string? jobLabel, string language, string? jobSearchLink = null, int expiryDays = 7);
+
+        /// <summary>
+        /// Returns the localised label for a manually-entered job description (no URL provided).
+        /// </summary>
+        /// <param name="language">Two-letter language code.</param>
+        string GetManualJobLabel(string language);
     }
 }