feat(bf): put the HOST27 deal on the homepage; deal window now starts 2 November

The coupon applies today (signed-out test: post_basket -> /coupon/HOST27 ->
cart 295.00 from a 395.00 list), so the offer starts today, not on 16 November.

- index.html: one seasonal banner above the hero, a single <a> to
  /odoo-black-friday/. Homepage components and CI only (midnight/brass/cream,
  Marcellus/Inter). No script, no tracking tag, no event: the homepage has no
  consent gate, so nothing measurable may be added there. Hero, server
  selector, section order and JSON-LD untouched. Dated for removal after
  30 November 2026.
- odoo-black-friday/: every start claim 16 -> 2 (meta, og:image:alt, JSON-LD
  WebPage description + two FAQ answers, hero-sub, two body FAQ answers).
  End date, countdown instant, forms, consent gate and the three conversions
  unchanged.
- odoo-hosting-offers/: same start claim on the second ad lander, so the AG1
  visitor is not told the deal begins in two weeks.

Every price claim keeps the "first year" qualifier.

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' and 'Save $100 on Odoo hosting', with a secret deal on the Bootcamp."
+      content="Black Friday 2026 poster: 'Black Friday — 2–30 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" />
@@ -479,10 +479,10 @@
     <!-- Date-scoped Black Friday block -->
     <section class="section-light">
       <div class="container">
-        <!-- BF-BLOCK-START: live 16–30 November 2026 only. Remove this block after 30 Nov 2026. -->
+        <!-- BF-BLOCK-START: live 2–30 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. The window is 16–30 November 2026, and it ends on Cyber Monday.</p>
+          <p class="bf-hub-line">This November we take $100 off your first year of hosting. The window is 2–30 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. -->
           <!-- Buy = CLICK PROXY (offer-CTA click), NOT a sale. The real purchase event is fired on the
                checkout host (20.odoo4projects.com) by odoo-dev. See wiki/concepts/conversion-tracking-contract. -->