fix(bootcamp): Buy forms add the Q1 2027 cohort (product 12 -> 17)

All nine Buy forms on the bootcamp pages (EN/DE/ES, three each) posted
product_id 12, which the shop resolves to 'Bootcamp - Q1-2026-eng'. The
advertised cohort is Q1 2027 (starts Thu 21 Jan 2027), so a customer
buying the 2027 bootcamp received the 2026 cohort. Both are 595.00 and
neither cart was empty, so it went unnoticed; the form's info field reads
'Q1 2027, English' while the product was 2026.

product_id 12 -> 17 in every bootcamp Buy form, all three languages.
The info field is kept (it renders as the cart line description via
sale.order.line.name, so it is read downstream); it is truthful.
static/buy.js doc comment updated to match. Nothing else changed:
plausible-event-name=Buy class, target=_blank form post, prices and
layout untouched.

de/odoo-erp-automation-bootcamp/index.html

@@ -591,7 +591,7 @@
         </div>
         <div class="hero-actions">
           <form method="post" action="https://20.odoo4projects.com/shop/post_basket" target="_blank" class="plausible-event-name=Buy">
-            <input type="hidden" name="basket" value='[{"product_id":12,"qty":1,"info":"Q1 2027, English"}]' />
+            <input type="hidden" name="basket" value='[{"product_id":17,"qty":1,"info":"Q1 2027, English"}]' />
             <input type="hidden" name="clear" value="1" />
             <button type="submit" class="btn btn-brass btn-lg">Für 595.00 USD kaufen</button>
           </form>
@@ -612,7 +612,7 @@
         <p class="bc-subline">Drei Monate. Zehn Stunden Unterricht. Ein System, das Ihr Unternehmen steuert.</p>
         <div class="bc-action">
           <form method="post" action="https://20.odoo4projects.com/shop/post_basket" target="_blank" class="plausible-event-name=Buy">
-            <input type="hidden" name="basket" value='[{"product_id":12,"qty":1,"info":"Q1 2027, English"}]' />
+            <input type="hidden" name="basket" value='[{"product_id":17,"qty":1,"info":"Q1 2027, English"}]' />
             <input type="hidden" name="clear" value="1" />
             <button type="submit" class="btn btn-brass btn-lg">Für 595.00 USD kaufen</button>
           </form>
@@ -777,7 +777,7 @@
         </p>
         <div class="bc-action">
           <form method="post" action="https://20.odoo4projects.com/shop/post_basket" target="_blank" class="plausible-event-name=Buy">
-            <input type="hidden" name="basket" value='[{"product_id":12,"qty":1,"info":"Q1 2027, English"}]' />
+            <input type="hidden" name="basket" value='[{"product_id":17,"qty":1,"info":"Q1 2027, English"}]' />
             <input type="hidden" name="clear" value="1" />
             <button type="submit" class="btn btn-brass btn-lg">Für 595.00 USD kaufen</button>
           </form>