Convert barant.com JET 1.4 marketing pages to jetc/.jtc (local, non-production)

Pulls .page files and shared template infrastructure (mainpagetemplate.temp,
menu.bar, barant.tag, opensource.menu, cart.menu, login.menu) read-only from
barant.com via SFTP into jetc/barant-site/src, then convert.py mechanically
flattens them into self-contained .jet files: linkbutton becomes a plain
anchor link (the old SESSIONCTL PAGE/PROCESS form-postback model has no
equivalent here - each page is its own real #api route now, not a shared
single-form state machine), sectionframe is expanded per its barant.tag
definition, /images/* references are fetched and inlined as data URIs
(APIServer has no static-file serving), and session-gated chrome (cart,
account/admin, login.menu) is resolved to its anonymous-visitor default
state, since no session/DB backend is wired into this conversion.

17 pages convert and serve cleanly end-to-end (verified via a local
apiserver-barant-site.json instance on :8081, kept separate from the
existing demo server on :8080 to avoid a /main route collision with the
earlier hand-cloned barant.jet). Two pages deliberately out of scope for
this pass: davidarant.page (whiledir filesystem iteration) and the
per-topic sub-pages of jet.page (dispatches on an ARGS query param this
conversion does not populate - only the default overview state converts).
vst.page/modular1.page/modular1_patches.page also deferred - they pull
live product rows via sql, a real backend dependency beyond "pages and
their template" scope.

Nothing was written back to barant.com - SFTP access was read-only
throughout, per explicit instruction to convert locally without touching
the original site.

jetc/barant-site/src/checkout.page

@@ -0,0 +1,60 @@
+<page template="mainpagetemplate" loggedin="yes">
+<title>SHOPPING CART - CHECKOUT</title>
+<script src="https://web.squarecdn.com/v1/square.js"></script>
+<contents>
+ <script> 
+   function processCardForm(token) {
+     xhr = new XMLHttpRequest();
+     xhr.open('POST', '/pp.cgi', true);
+     xhr.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');
+     xhr.onload = function () {
+       console.log(">" + this.responseText + "<");
+       if(this.responseText == "OK\n") {
+         document.forms[0].PAGE.value = 'thankyou';
+         document.forms[0].submit();
+       } else {  
+	 message.innerText = this.responseText;     
+       }
+     };
+     let data = 'id=$[_session_id]&token=' + token + '&tranonce=$[tranonce]';
+     xhr.send(data); 
+   }
+   var card;
+   async function buildForm() {
+     let payments = Square.payments('sq0idp-V4R4vEferpF9kr7d5x5abQ','LV0MRENX5ED3Z');
+     const card = await payments.card({
+       style: {
+         '.input-container.is-focus': { borderColor: '#006AFF' },
+	 '.message-text.is-error': { color: '#BF0020' }
+       }
+     });
+     await card.attach('#card');
+     let button = document.getElementById('pay');
+     button.addEventListener('click', async () => {
+       let result = await card.tokenize();
+       if (result.status === 'OK') {
+         let processbanner = document.getElementById('process');
+         processbanner.style.visibility = 'visible';
+         processCardForm(result.token);
+       }
+     });
+  }
+  buildForm();   
+</script>
+<sql>select count(*) as number_of_items,
+            sum(price * quantity) as total 
+	    from product_list
+            join cart_item on product_list.sku=cart_item.sku
+            where cart_item.session_uuid='$[_session_id]'
+</sql>
+<sectionframe title="Pay with Credit Card">
+<div>Please enter your payment information:</div>
+<div style="font-size: 20px;">$[total]</div>
+<div id="card" style="background-color: #ddd;width: 300px; padding: 5px;"></div>
+<div style="padding: 5px;"><button id= "pay" type="button">Pay</button></div>
+<div id="process" style="background-color: #0f0; border: 2px solid #000; padding:
+5px; display: block-inline; margin: 10px; visibility: hidden;"> Processing Payment - Please wait... </div>
+<div id="message" style="color: #f00; margin-top: 20px;"></div>
+</sectionframe>
+</contents>
+</page>