Add global music player, invoicing/payment system, account subpages, mail account admin, and the qualityiron.vegas Jet 2.0 port

Jet interpreter (Tag.cpp, __call.cpp, __imap*.cpp/h, __smtpsend.cpp/h,
__imapemptyfolder.cpp/h - new): assorted parser/tag fixes found across
this work - a stray literal-tag-in-comment and backslash-quote parser
corruption class, a dangling-pointer fix, a __call.cpp fd leak, IMAP
folder-management tags, multi-account/per-host IMAP support, and a
smtpsend Message-ID fix.

barant.com site (jetc/barant-site/):
- A site-wide persistent music player (header band, playlist/queue,
  stereo FFT EQ, session-persisted state) fed by new library/
  ianslibrary/music song-list subpages.
- /account split into info/phones/invoices subpages; a full invoicing
  and Square payment system (create/edit/copy/pay/email invoice);
  admin invoice management and mail-account management subpages.
- /services split into overview/hosting/siptrunking/documents
  subpages, retiring the old standalone pages.
- SIPPHONE.tag: a Jet 2.0 WebRTC softphone tag.
- main.css/spa.js/email.js: the SPA loading indicator, the music
  player band styling, and assorted fixes accumulated alongside this
  work.

qualityiron-site/: the qualityiron.vegas job/contractor/customer/
document management app, ported from its original Jet 1.4 codebase to
Jet 2.0 as barant.coms APIServers second multi-tenant site.

wcwc/wcwc.jet: the WCWC site Jet source (wcwc.jtc build output not
included).

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

__imap.cpp

@@ -559,8 +559,15 @@ namespace jet {
       coreutils::MString passwordVal = resolveKeyword("password");
 
       coreutils::JFile config(configPath);
-      std::string host = config.getString("host");
-      long port = (long)config.getNumber("port");
+      // host/port keywords override the config file's own values when
+      // present - lets a caller reuse one config file (still needed for
+      // caCertificate/smtpPort) across many accounts that each live on
+      // a different mail server, rather than requiring a separate config
+      // file per server. Every existing caller omits these keywords, so
+      // behavior is unchanged for them - config's own host/port is still
+      // the only thing read in that case.
+      std::string host = keywordDefined("host") ? resolveKeyword("host").str() : config.getString("host");
+      long port = keywordDefined("port") ? strtol(resolveKeyword("port").str().c_str(), nullptr, 10) : (long)config.getNumber("port");
       if (port <= 0)
          port = 993;
 
@@ -1034,6 +1041,24 @@ namespace jet {
       return coreutils::MString(std::string("{\"ok\":") + (ok ? "true" : "false") + "}");
    }
 
+   coreutils::MString __imap::emptyFolder(const std::string &folder) {
+      if (!selectFolderIfNeeded(folder))
+         throw coreutils::Exception("imap: could not select folder " + folder, __FILE__, __LINE__, 502);
+
+      std::string tag = nextTag();
+      sendLine(tag + " UID STORE 1:* +FLAGS (\\Deleted)");
+      auto lines = readUntilTagged(tag);
+      bool ok1 = taggedOk(lines, tag);
+
+      std::string tag2 = nextTag();
+      sendLine(tag2 + " EXPUNGE");
+      auto lines2 = readUntilTagged(tag2);
+      bool ok2 = taggedOk(lines2, tag2);
+
+      bool ok = ok1 && ok2;
+      return coreutils::MString(std::string("{\"ok\":") + (ok ? "true" : "false") + "}");
+   }
+
    // BARANTMail (see __IMAP_COPY.cpp) implements COPY but not the
    // RFC 6851 MOVE extension - not surprising, since the whole point
    // of that extension was standardizing what every real-world client