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>

jetc/barant-site/src/admin-invoice.subpage

@@ -0,0 +1,46 @@
+<include file="invoice.method">
+<br>
+<linkbutton page="editinvoice"><div class="button">Edit Invoice</div></linkbutton>
+<div style="margin-top: 10px; display: flex; align-items: center; gap: 6px;">
+ <input type="email" id="mail_invoice_email" placeholder="recipient@example.com" style="width: 220px;">
+ <button type="button" id="mail_invoice_btn" class="button">Mail Invoice</button>
+ <span id="mail_invoice_status" style="font-size: 12px; color: var(--bond-text-dim);"></span>
+</div>
+<script>
+(function() {
+  var btn = document.getElementById('mail_invoice_btn');
+  var input = document.getElementById('mail_invoice_email');
+  var status = document.getElementById('mail_invoice_status');
+  if (!btn || !input || !status) return;
+  btn.addEventListener('click', function() {
+    var email = input.value.trim();
+    if (!email) {
+      status.textContent = 'Enter an e-mail address first.';
+      status.style.color = '#a13a3a';
+      return;
+    }
+    btn.disabled = true;
+    status.textContent = 'Sending…';
+    status.style.color = 'var(--bond-text-dim)';
+    fetch('/admin/mail-invoice', {
+      method: 'POST',
+      credentials: 'same-origin',
+      headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
+      body: new URLSearchParams({ email: email }).toString()
+    }).then(function(r) { return r.json(); }).then(function(res) {
+      btn.disabled = false;
+      if (res.ok) {
+        status.textContent = 'Invoice emailed to ' + email + '.';
+        status.style.color = '#6fb8c9';
+      } else {
+        status.textContent = res.error || 'Could not send the invoice.';
+        status.style.color = '#a13a3a';
+      }
+    }).catch(function() {
+      btn.disabled = false;
+      status.textContent = 'Request failed. Please try again.';
+      status.style.color = '#a13a3a';
+    });
+  });
+})();
+</script>