fix(marketing): A-2.8a — extract pricing partial + sync bento + OQLF + test calibration

- Extract 3 pricing tiers to templates/marketing/_partials/_pricing_tiers.html
  Single source of truth — landing.html and tarifs.html now {% include %} it.
  Prevents price drift (LPC art. 219 risk).
- Sync bento card #2 description across landing + fonctionnalites
  (was diverged: 'embeddings' vs 'embeddings vocaux'). Add maintenance
  reminder comments in both files.
- Fix OQLF NBSP on '~2 semaines' matrix cells in /tarifs deep-dive table.
- Fix mixed UTF-8/entity 'québécois' -> 'québécois' in tech
  specs (consistent with rest of file).
- Calibrate H2 size on /tarifs FAQ to match landing (clamp 2.75rem cap).
- Repair 2 pre-existing test bugs from earlier A-2.x commits:
  * 'violent la Loi 25' -> accept both NBSP and plain forms (commit 7c6c6fd
    added the NBSP after the test was written)
  * 'résilie' -> 'résilie' (Jinja outputs raw UTF-8, not entities)
- Update src/marketing/routes.py module docstring to reflect 2/4 done.

templates/marketing/_partials/_pricing_tiers.html

@@ -0,0 +1,30 @@
+{# Single source of truth for the 3 pricing tiers — used by landing.html#tarifs and /tarifs page.
+   When prices change, edit ONLY this file. #}
+{% from 'macros/pricing_card.html' import pricing_card %}
+<div class="grid md:grid-cols-3 gap-6 max-w-5xl mx-auto items-stretch">
+  {{ pricing_card(
+    'dictia-8',
+    'DictIA 8',
+    '3&nbsp;450&nbsp;$',
+    '173&nbsp;$',
+    'PME · RH · Manufacturiers',
+    ['GPU 8&nbsp;Go RTX', 'Volume illimité', 'WhisperX FR-CA', 'Diarisation 8 locuteurs', 'Support inclus']
+  ) }}
+  {{ pricing_card(
+    'dictia-16',
+    'DictIA 16',
+    '5&nbsp;750&nbsp;$',
+    '201&nbsp;$',
+    'Cabinets juridiques · CPA · Finance',
+    ['GPU 16&nbsp;Go RTX', 'Mistral 7B local', 'Q&amp;R sur enregistrement', 'Tout DictIA 8', 'Support prioritaire'],
+    recommended=True
+  ) }}
+  {{ pricing_card(
+    'dictia-cloud',
+    'DictIA Cloud',
+    '0&nbsp;$',
+    '369&nbsp;$',
+    'Organismes · Municipalités · Multi-sites',
+    ['Hébergé OVH Beauharnois (Québec)', 'Opérationnel sous 48&nbsp;h', 'Aucun matériel à gérer', 'SLA visé 99,9&nbsp;%', 'Conforme Loi&nbsp;25']
+  ) }}
+</div>