feat(seo): wire internal links between the 17 blog posts and the pages that sell

The blog was an island: zero post→page links to hosting/upgrade/support/courses,
and only one page→post link in the whole site. Posts ranked for nothing while the
old blog host ranked for our long-tail queries.

Posts → pages (26 new in-body contextual links across 17 posts):
each post now carries one or two links to the page that answers its reader's next
question — odoo-hosting-2027, odoo-community-upgrade, support, the workshops hub,
the n8n masterclass, and the plan pricing on index.html#pricing.

Pages → posts (7 pages, one contextual link each):
index.html (OCA section), odoo-hosting-2027, odoo-community-upgrade, support,
workshops/, odoo-n8n-masterclass/, odoo-erp-automation-bootcamp/ now link into the
post that fits their own subject. The clearest miss is fixed — the
community-vs-enterprise-cost post and the odoo-community-upgrade page now link
to each other.

Anchors wrap existing sentences where the text already said the thing; four short
linking sentences were added (index OCA section, support first-steps FAQ, masterclass
lessons, bootcamp included section). No new components, no related-posts widget,
in-body anchors only. English pages only; DE/ES untouched (translator follow-up).

blog/posts/track-the-oca-modules-you-actually-use.html

@@ -120,11 +120,11 @@
                 <div class="post-content">
 <p>Every new Odoo release starts the same routine. You install the latest version, open a browser, and begin clicking through your favourite OCA repositories to find out which modules have been ported — and which ones you will have to live without for a while.</p>
 
-<p>We do the same thing. So we automated it. Our homepage now carries a live table of the OCA modules we rely on most, checked and updated by our robots on a daily basis.</p>
+<p>We do the same thing. So we automated it. Our <a href="../../index.html#ocaModules">homepage</a> now carries a live table of the OCA modules we rely on most, checked and updated by our robots on a daily basis.</p>
 
 <h2>Why a tracker is worth having</h2>
 
-<p>OCA porting work happens at its own pace. Maintainers volunteer their time, and a module that is solid on one version can sit unported on the next for weeks or months. Checking manually means guessing, and guessing during an upgrade project is expensive — you plan around a module that is not ready, or you delay a migration that was actually fine to start.</p>
+<p>OCA porting work happens at its own pace. Maintainers volunteer their time, and a module that is solid on one version can sit unported on the next for weeks or months. Checking manually means guessing, and guessing during an <a href="../../odoo-community-upgrade.html">upgrade project</a> is expensive — you plan around a module that is not ready, or you delay a migration that was actually fine to start.</p>
 
 <p>A tracker turns that guesswork into a glance. That is the whole point.</p>