Generalize mail templates from a fixed pair to an operator-managed list

ArchiveKind was a hardcoded two-value enum (ssh_access/config_update),
wired through FilenameParser's regex, MailTemplateSet's two fixed
slots, and SettingsForm's two fixed tabs. Operators wanted arbitrary
custom templates (own file-name suffix, subject, body) without a code
change per new archive kind ssh-access-tui might start producing.

Replaced with MailTemplateDefinition (DisplayName/FileSuffix/Subject/
BodyHtml) in an open-ended list: FilenameParser now accepts any
"{login}_{suffix}.7z" and ArchiveScanner matches the suffix against
the configured list; SendJob.Kind/SendLogEntry.Kind became plain
strings; SettingsForm gained a template list (+/- buttons, editor
panel) replacing the two static tabs. ssh_access/config_update are now
just the two default entries in that list, not special-cased.

Handles the two backward-compat edges that matter for a tool already
in real use: old config.json's object-shaped "templates" migrates to
the new list shape transparently on first load (DataContractJsonSerializer
turned out to silently produce an empty list rather than throw on the
old shape, so detection is structural, not exception-based), and old
send-log.csv rows with PascalCase Kind values (SshAccess/ConfigUpdate)
still dedupe correctly against the new snake_case suffixes.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

outlook-bulk-sender/BulkArchiveMailer.Core/ArchiveScanner.cs

@@ -26,9 +26,9 @@ namespace BulkArchiveMailer.Core
     {
         /// <param name="folderPath">Folder to scan (non-recursive - ssh-access-tui writes archives flat into one output directory).</param>
         /// <param name="emailDomain">Domain appended to the derived local part, e.g. "redlab.lo".</param>
-        /// <param name="templates">Used to render each Ready job's Subject/BodyHtml. May be null (rows are then created with empty Subject/BodyHtml, useful for pure filename-parsing tests).</param>
+        /// <param name="templates">Configured templates, matched against each parsed file's suffix (case-insensitively) to render that job's Subject/BodyHtml/KindDisplay. May be null or empty (every recognized file then goes to UnrecognizedFiles, since nothing can match), useful for pure filename-parsing tests.</param>
         /// <param name="sendLog">When provided, each single-archive login is checked against the log (by SHA-256 of the archive's current bytes) and marked AlreadySent if a prior Sent row matches. When null, dedup is skipped entirely and every recognized single-archive login comes back Ready.</param>
-        public static ScanResult Scan(string folderPath, string emailDomain, MailTemplateSet templates, SendLogStore sendLog = null)
+        public static ScanResult Scan(string folderPath, string emailDomain, List<MailTemplateDefinition> templates, SendLogStore sendLog = null)
         {
             var result = new ScanResult();
 
@@ -41,9 +41,9 @@ namespace BulkArchiveMailer.Core
                 return result;
             }
 
-            // login -> every (path, kind) found for it, case-insensitive
+            // login -> every (path, suffix) found for it, case-insensitive
             // because the file system this runs on (Windows) is too.
-            var byLogin = new Dictionary<string, List<(string Path, ArchiveKind Kind)>>(StringComparer.OrdinalIgnoreCase);
+            var byLogin = new Dictionary<string, List<(string Path, string Suffix)>>(StringComparer.OrdinalIgnoreCase);
 
             foreach (var filePath in Directory.EnumerateFiles(folderPath, "*.7z", SearchOption.TopDirectoryOnly).OrderBy(p => p, StringComparer.OrdinalIgnoreCase))
             {
@@ -55,18 +55,30 @@ namespace BulkArchiveMailer.Core
                     {
                         ArchivePath = filePath,
                         Status = SendStatus.Skipped,
-                        ErrorMessage = $"Имя файла не соответствует шаблону \"{{login}}_ssh_access.7z\" / \"{{login}}_config_update.7z\": {fileName}",
+                        ErrorMessage = $"Имя файла не соответствует шаблону \"{{login}}_{{суффикс}}.7z\": {fileName}",
+                    });
+                    continue;
+                }
+
+                var matchedTemplate = templates?.FirstOrDefault(t => string.Equals(t.FileSuffix, parsed.Suffix, StringComparison.OrdinalIgnoreCase));
+                if (matchedTemplate == null)
+                {
+                    result.UnrecognizedFiles.Add(new SendJob
+                    {
+                        ArchivePath = filePath,
+                        Status = SendStatus.Skipped,
+                        ErrorMessage = $"Суффикс \"{parsed.Suffix}\" не соответствует ни одному настроенному шаблону: {fileName}",
                     });
                     continue;
                 }
 
                 if (!byLogin.TryGetValue(parsed.Login, out var list))
                 {
-                    list = new List<(string, ArchiveKind)>();
+                    list = new List<(string, string)>();
                     byLogin[parsed.Login] = list;
                 }
 
-                list.Add((filePath, parsed.Kind));
+                list.Add((filePath, parsed.Suffix));
             }
 
             foreach (var kv in byLogin.OrderBy(k => k.Key, StringComparer.OrdinalIgnoreCase))
@@ -95,19 +107,21 @@ namespace BulkArchiveMailer.Core
                     continue;
                 }
 
-                var (path, kind) = files[0];
-                var rendered = templates != null
-                    ? TemplateEngine.Render(templates.Get(kind), login, email)
-                    : new MailTemplate();
+                var (path, suffix) = files[0];
+                // Guaranteed non-null: a suffix only ever makes it into
+                // byLogin after already matching a template above.
+                var matchedTemplate = templates.First(t => string.Equals(t.FileSuffix, suffix, StringComparison.OrdinalIgnoreCase));
+                var values = TemplateEngine.BuildValues(login, email);
 
                 var job = new SendJob
                 {
                     Login = login,
                     Email = email,
-                    Kind = kind,
+                    Kind = suffix,
                     ArchivePath = path,
-                    Subject = rendered.Subject,
-                    BodyHtml = rendered.BodyHtml,
+                    Subject = TemplateEngine.Render(matchedTemplate.Subject, values),
+                    BodyHtml = TemplateEngine.Render(matchedTemplate.BodyHtml, values),
+                    KindDisplay = matchedTemplate.DisplayName,
                     Status = SendStatus.Ready,
                 };
 
@@ -116,7 +130,7 @@ namespace BulkArchiveMailer.Core
                     try
                     {
                         job.FileSha256 = SendLogStore.ComputeSha256(path);
-                        if (sendLog.TryFindSent(email, kind, job.FileSha256, out var priorEntry))
+                        if (sendLog.TryFindSent(email, suffix, job.FileSha256, out var priorEntry))
                         {
                             job.Status = SendStatus.AlreadySent;
                             job.ErrorMessage = $"Уже отправлено {priorEntry.TimestampUtc:yyyy-MM-dd HH:mm} UTC (тот же файл, без изменений с тех пор).";