Add per-domain DKIM signing, admin console TLS, log rotation, and resolver timeout scoping

- DKIM signing was hardcoded to one domain; now keyed per-domain off
  the sending address, fixing mail for every domain but the original.
- Admin console (port 1027) is now TLS-wrapped instead of plaintext.
- barantmail.log now rotates by size (config-driven) instead of
  growing unbounded (previously hit 23GB).
- ResolverThreadScope.h: a <setenv> scoping fix for name resolution
  inside a <try> block that previously did not survive its own
  container.
- IMAPArgs.cpp: fixed "UID STORE 1:*" wrongly requiring UID 1 to
  exist, which silently made empty-folder operations delete nothing.

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

SMTPServer.cpp

@@ -9,8 +9,8 @@ namespace mail {
 
    SMTPServer::SMTPServer(core::EPoll &ePoll, std::string hostName, MailFileSystem &mailFileSystem,
                           core::IPAddress ipAddress, core::TLSInfo *tlsInfo, bool watchQueue,
-                          DKIMSigner *dkimSigner)
-	: core::TCPServer(ePoll, ipAddress, tlsInfo, " ", 1, "SMTP Server"), core::INotify(ePoll), ePoll(ePoll), hostName(hostName), mailFileSystem(mailFileSystem), dkimSigner(dkimSigner) {
+                          std::map<std::string, DKIMSigner*> *dkimSigners)
+	: core::TCPServer(ePoll, ipAddress, tlsInfo, " ", 1, "SMTP Server"), core::INotify(ePoll), ePoll(ePoll), hostName(hostName), mailFileSystem(mailFileSystem), dkimSigners(dkimSigners) {
 	   commands.add(_smtp_auth, "AUTH");
 	   commands.add(_smtp_data, "DATA");
 	   commands.add(_smtp_ehlo, "EHLO");
@@ -114,7 +114,7 @@ namespace mail {
             queuedFile.read();
             coreutils::MString mailData(queuedFile.asString());
             SendMail *outbound = new SendMail(hostName, mailFileSystem.getSendLogPath().str(),
-                                               name[0].str(), sender, recipient, mailData, dkimSigner);
+                                               name[0].str(), sender, recipient, mailData, dkimSigners);
             // The queue file's content is already fully read into
             // mailData above, so it's safe to unlink it now rather
             // than after the detached thread finishes (which may be