Complete S01 Gmail matching and import workflow

JobTrackerApi/Services/GmailOAuthService.cs

@@ -18,6 +18,7 @@ public interface IGmailOAuthService
     Task<GmailConnection?> GetConnectionAsync(string ownerUserId, CancellationToken cancellationToken);
     Task DisconnectAsync(string ownerUserId, CancellationToken cancellationToken);
     Task<IReadOnlyList<GmailMessageSummary>> ListMessagesAsync(string ownerUserId, string? query, int maxResults, CancellationToken cancellationToken);
+    Task<IReadOnlyList<GmailMessageSummary>> ListMessagesForQueriesAsync(string ownerUserId, IEnumerable<string> queries, int maxResultsPerQuery, CancellationToken cancellationToken);
     Task<GmailMessageDetail> GetMessageAsync(string ownerUserId, string messageId, CancellationToken cancellationToken);
 }
 
@@ -180,6 +181,33 @@ public sealed class GmailOAuthService : IGmailOAuthService
         return results;
     }
 
+    public async Task<IReadOnlyList<GmailMessageSummary>> ListMessagesForQueriesAsync(string ownerUserId, IEnumerable<string> queries, int maxResultsPerQuery, CancellationToken cancellationToken)
+    {
+        maxResultsPerQuery = Math.Clamp(maxResultsPerQuery, 1, 25);
+        var normalizedQueries = queries
+            .Where(static query => !string.IsNullOrWhiteSpace(query))
+            .Select(static query => query.Trim())
+            .Distinct(StringComparer.OrdinalIgnoreCase)
+            .ToList();
+
+        if (normalizedQueries.Count == 0)
+        {
+            return Array.Empty<GmailMessageSummary>();
+        }
+
+        var combined = new List<GmailMessageSummary>();
+        foreach (var query in normalizedQueries)
+        {
+            var items = await ListMessagesAsync(ownerUserId, query, maxResultsPerQuery, cancellationToken);
+            combined.AddRange(items);
+        }
+
+        return combined
+            .GroupBy(message => message.Id, StringComparer.Ordinal)
+            .Select(group => group.First())
+            .ToList();
+    }
+
     public async Task<GmailMessageDetail> GetMessageAsync(string ownerUserId, string messageId, CancellationToken cancellationToken)
     {
         var accessToken = await GetValidAccessTokenAsync(ownerUserId, cancellationToken);