fix(bf): strip the last off-panel mentions of the discount code

The code may not be named where a visitor or crawler can read it before
opening a reveal panel. Three off-panel leaks removed:

- /odoo-black-friday/ FAQ (visible answer + its FAQPage JSON-LD twin,
  byte-identical): 'the code stops working' -> 'the offer stops working'.
- /odoo-hosting-offers/ og:image:alt: the trailing ', and the code
  HOST27' dropped; the offer and the 16-30 November window stay.
- /odoo-hosting-offers/ date-scoped Black Friday block: the line no
  longer names the code; it states the offer and links to
  /odoo-black-friday/ (the only page with a reveal panel), marked with a
  dated comment for removal after 30 November 2026.

HOST27 now survives only inside the .bf-panel on /odoo-black-friday/;
/odoo-hosting-offers/ carries zero.

odoo-hosting-offers/index.html

@@ -21,7 +21,7 @@
     <meta property="og:image:height" content="630" />
     <meta
       property="og:image:alt"
-      content="Black Friday 2026 poster: 'Black Friday — 16–30 November', 'Save $100 on Odoo hosting' with a secret deal on the Bootcamp, and the code HOST27."
+      content="Black Friday 2026 poster: 'Black Friday — 16–30 November' and 'Save $100 on Odoo hosting', with a secret deal on the Bootcamp."
     />
     <meta name="twitter:card" content="summary_large_image" />
     <meta name="twitter:image" content="https://odoo4projects.com/images/black-friday/bf2026-hosting-og.png" />
@@ -482,8 +482,9 @@
         <!-- BF-BLOCK-START: live 16–30 November 2026 only. Remove this block after 30 Nov 2026. -->
         <div class="bf-hub">
           <h2>Black Friday and Cyber Monday 2026</h2>
-          <p class="bf-hub-line">This November we take $100 off your first year of hosting with code <strong>HOST27</strong>. The window is 16–30 November 2026, and it ends on Cyber Monday.</p>
-          <p class="bf-hub-link"><a href="/odoo-black-friday/">See the Black Friday hosting offer</a></p>
+          <p class="bf-hub-line">This November we take $100 off your first year of hosting. The window is 16–30 November 2026, and it ends on Cyber Monday.</p>
+          <!-- 2026-11-01, dated for removal: the offer and the code are revealed on /odoo-black-friday/ only. Remove this link with the BF block after 30 November 2026. -->
+          <p class="bf-hub-link"><a href="/odoo-black-friday/">See the Black Friday offer</a></p>
         </div>
         <!-- BF-BLOCK-END -->
       </div>