feat(analytics): add Plausible custom-event markings for six goals

Mark the six conversion goals on the self-hosted Plausible instance so the
events match the goals to be registered in Plausible. Event names verbatim:
Trial, FAQ, Buy, Custom Quote, search posts, Project Plan.

CSS-class markings (work without JS logic, on the clickable element):
- FAQ  -> index/de/es index .faq-card; odoo-hosting-2027 + odoo-community-upgrade
          (de/es twins) and australia <summary>; support.html .faq-question
- Buy  -> index/de/es index .btn-buy anchors; australia + bootcamp native
          post_basket submit buttons (forms stay native POST)

JS call markings in script.js (loaded by index, de/index, es/index):
- Trial        on the successful trial-form POST (.then branch)
- Custom Quote on the successful custom-quote POST (.then branch)
- Project Plan on the successful business-wizard submit
- search posts on the FIRST input of #blogSearch only (guard flag, one per
  pageview, not on every keystroke, not on #ocaSearch)

Nothing fires on page load; the 'Start the free trial' anchors that only
scroll to #trialCard are deliberately not tagged. One goal per topic across
all languages, no language suffix. No visual, behavioural or request change.

odoo-hosting-2027.html

@@ -916,37 +916,37 @@
         <h2 class="section-title">Questions the table raises</h2>
         <div class="cmp-faq-grid">
           <details class="cmp-faq">
-            <summary>What does "five minutes" actually mean?</summary>
+            <summary class="plausible-event-name=FAQ">What does "five minutes" actually mean?</summary>
             <div class="cmp-a">
               <p>Five minutes is the time to a running instance, not to a finished system. Putting your own customers, products and stock in is the first week's work, and it is the same week on any of the routes above.</p>
             </div>
           </details>
           <details class="cmp-faq">
-            <summary>Do you support Odoo Online?</summary>
+            <summary class="plausible-event-name=FAQ">Do you support Odoo Online?</summary>
             <div class="cmp-a">
               <p>No. Odoo Online runs Odoo's standard apps only and is incompatible with custom modules or modules from the Odoo Apps Store, so you cannot add an app that is not on Odoo's list. Upgrades are automatic and mandatory on Odoo's schedule. If Odoo's standard apps cover everything you will ever need, Odoo Online is the cheaper and simpler answer and we are not the right choice.</p>
             </div>
           </details>
           <details class="cmp-faq">
-            <summary>Can I add my own apps or OCA modules?</summary>
+            <summary class="plausible-event-name=FAQ">Can I add my own apps or OCA modules?</summary>
             <div class="cmp-a">
               <p>Odoo's own apps are all there on every plan. Custom and OCA modules install from On the Rise up, by Git or one click. Side Hustle has no module installation.</p>
             </div>
           </details>
           <details class="cmp-faq">
-            <summary>Do I need an AI assistant to use ODOO4projects?</summary>
+            <summary class="plausible-event-name=FAQ">Do I need an AI assistant to use ODOO4projects?</summary>
             <div class="cmp-a">
               <p>No. We ship our MCP server directly in the apps, so an AI assistant such as Claude Code or Hermes can restart the server, upload a module, add a domain or read the log for you, and you never open a hosting panel. It is optional: the business works exactly the same without it.</p>
             </div>
           </details>
           <details class="cmp-faq">
-            <summary>Can we move to Odoo Enterprise later?</summary>
+            <summary class="plausible-event-name=FAQ">Can we move to Odoo Enterprise later?</summary>
             <div class="cmp-a">
               <p>Yes. Bring your own Odoo Enterprise licence and keep the same instance. No migration.</p>
             </div>
           </details>
           <details class="cmp-faq">
-            <summary>Is there a per-user licence?</summary>
+            <summary class="plausible-event-name=FAQ">Is there a per-user licence?</summary>
             <div class="cmp-a">
               <p>No. Odoo Community has no per-user licence; our plans are one flat yearly price. Odoo Enterprise, if you bring it, is licensed per user by Odoo S.A.</p>
             </div>