refactor(ui): sharpen buttons + inputs to rounded (4px) for modern minimal SaaS look

V2 sharper radii system aligned with Stripe Dashboard / Linear / Vercel
aesthetic — the v1 rounded-lg (8px) on buttons still felt too soft.

New scale:
- Buttons (CTA, submit, ghost, secondary): rounded-lg → rounded (4px)
- Form inputs (text/email/password/select/textarea): rounded-md → rounded (4px)
- Checkboxes: rounded-sm (2px) added explicitly to consent + remember-me
- Cards (pricing, bento, content panels): rounded-xl → rounded-lg (8px)
- Small icon tiles (w-10 h-10 / w-12 h-12 grad-bg squares): rounded-md → rounded
- Pills, badges, avatars, status orbs: rounded-full (KEPT)
- Inline code in legal CSS: rounded (4px) (KEPT)
- Legal blockquote/pre/draft-callout border-radius: 8px → 4px

Files modified (24):
- templates/macros/{button,bento,pricing_card}.html
- templates/marketing/{landing,tarifs,fonctionnalites,conformite,contact}.html
- templates/auth/{check_email,forgot_password,magic_link_request,
  oauth_finish_signup,passkey_setup,reset_password,totp_setup,totp_verify,
  verify_success}.html
- templates/billing/{success,cancel}.html
- templates/legal/{_layout,index}.html
- templates/{register,login}.html
- tests/test_marketing_landing_template.py (assertions updated to match v2)

Verification:
- 18/18 legal page tests pass (tests/_run_legal_pages_windows.py)
- 58/58 marketing landing tests pass

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

templates/marketing/landing.html

@@ -176,7 +176,7 @@
         ('Précision FR-CA', 'WhisperX Large-v3 fine-tuné français québécois. Diarisation pyannote 8 locuteurs. Résumés Mistral 7B local — aucune connexion OpenAI/Google/Microsoft.')
       ] %}
       <article class="bg-white/[0.05] backdrop-blur-sm p-6 rounded-lg border border-white/[0.08]">
-        <div class="w-10 h-10 grad-bg rounded-md mb-4 flex items-center justify-center font-black text-white shadow-cta" aria-hidden="true">✓</div>
+        <div class="w-10 h-10 grad-bg rounded mb-4 flex items-center justify-center font-black text-white shadow-cta" aria-hidden="true">✓</div>
         <h3 class="text-lg font-bold mb-2 text-white">{{ pillar[0] | safe }}</h3>
         <p class="text-sm text-white/70 leading-relaxed">{{ pillar[1] | safe }}</p>
       </article>
@@ -198,7 +198,7 @@
     {# NOTE: bento card content is duplicated between landing.html and fonctionnalites.html.
        When editing, sync both files. Future refactor: extract to _partials/_bento_features.html. #}
     {% from 'macros/bento.html' import bento_card %}
-    <div class="grid grid-cols-1 sm:grid-cols-2 md:grid-cols-3 gap-[1.5px] bg-brand-border rounded-xl overflow-hidden">
+    <div class="grid grid-cols-1 sm:grid-cols-2 md:grid-cols-3 gap-[1.5px] bg-brand-border rounded-lg overflow-hidden">
       {{ bento_card('01', 'Transcription WhisperX', 'Large-v3 fine-tuné FR-CA. Précision 95&nbsp;%+ sur réunions, dictées, audiences (méthodologie disponible sur demande).', '🎙️') }}
       {{ bento_card('02', 'Diarisation 8 locuteurs', 'pyannote sépare automatiquement les intervenants. Identification par embeddings vocaux.', '👥') }}
       {{ bento_card('03', 'Résumés Mistral 7B', 'IA locale génère résumés, points d\'action et procès-verbaux. Aucune connexion cloud.', '📝') }}
@@ -225,7 +225,7 @@
     {% include 'marketing/_partials/_pricing_tiers.html' %}
 
     {# ROI CALCULATOR — Alpine.js, hypotheses transparentes pour LPC art. 219 hygiene #}
-    <div x-data="roiCalculator()" class="mt-16 max-w-3xl mx-auto bg-white p-8 rounded-xl border border-brand-border" aria-labelledby="roi-title">
+    <div x-data="roiCalculator()" class="mt-16 max-w-3xl mx-auto bg-white p-8 rounded-lg border border-brand-border" aria-labelledby="roi-title">
       <p class="eyebrow text-center grad-text mb-2">CALCULATEUR ROI</p>
       <h3 id="roi-title" class="text-2xl font-black text-center mb-6 text-brand-navy">Combien DictIA peut vous faire économiser&nbsp;?</h3>
       <div class="grid sm:grid-cols-3 gap-4 mb-6">
@@ -272,7 +272,7 @@
       </p>
     </div>
 
-    <div class="overflow-x-auto rounded-xl border border-brand-border">
+    <div class="overflow-x-auto rounded-lg border border-brand-border">
       <table class="w-full min-w-[720px] text-sm">
         <caption class="sr-only">Comparaison DictIA, Microsoft Teams Premium, Otter.ai Business, Whisper local sur 6 critères</caption>
         <thead class="bg-brand-bg">
@@ -332,7 +332,7 @@
           <tr class="hover:bg-brand-bg/50 transition-colors">
             <th scope="row" class="text-left p-4 font-semibold text-brand-navy/80">{{ row.critere | safe }}</th>
             <td class="p-4 text-center font-semibold text-brand-navy">
-              <span class="inline-block px-2 py-1 rounded-md bg-brand-b3/10 text-brand-navy">{{ row.dictia | safe }}</span>
+              <span class="inline-block px-2 py-1 rounded bg-brand-b3/10 text-brand-navy">{{ row.dictia | safe }}</span>
             </td>
             <td class="p-4 text-center text-brand-navy/70">{{ row.teams | safe }}</td>
             <td class="p-4 text-center text-brand-navy/70">{{ row.otter | safe }}</td>
@@ -391,7 +391,7 @@
         }
       ] %}
       <article class="bg-white/[0.05] backdrop-blur-sm p-6 rounded-lg border border-white/[0.08]">
-        <div class="w-10 h-10 grad-bg rounded-md mb-4 flex items-center justify-center text-lg shadow-cta" aria-hidden="true">{{ card.icon }}</div>
+        <div class="w-10 h-10 grad-bg rounded mb-4 flex items-center justify-center text-lg shadow-cta" aria-hidden="true">{{ card.icon }}</div>
         <h3 class="text-lg font-bold mb-2 text-white">{{ card.title | safe }}</h3>
         <p class="text-sm text-white/80 leading-relaxed">{{ card.desc | safe }}</p>
       </article>
@@ -421,7 +421,7 @@
 
     <div class="grid md:grid-cols-3 gap-6">
       {% for t in testimonials %}
-      <article class="bg-white p-6 rounded-xl border border-brand-border flex flex-col items-center text-center"
+      <article class="bg-white p-6 rounded-lg border border-brand-border flex flex-col items-center text-center"
                aria-label="Témoignage {{ t.placeholder_label }} à venir">
         <div class="w-16 h-16 rounded-full grad-bg flex items-center justify-center mb-4 shadow-cta" aria-hidden="true">
           {%- if t.persona == 'avocat' -%}<span class="text-2xl">⚖️</span>
@@ -459,7 +459,7 @@
       <div x-data="{ open: false }" class="py-2" role="listitem">
         <h3>
           <button type="button"
-                  class="w-full flex items-center justify-between gap-4 py-4 text-left hover:bg-brand-bg/50 transition-colors rounded-md px-2 focus-visible:outline-2 focus-visible:outline-brand-b1 focus-visible:outline-offset-2"
+                  class="w-full flex items-center justify-between gap-4 py-4 text-left hover:bg-brand-bg/50 transition-colors rounded px-2 focus-visible:outline-2 focus-visible:outline-brand-b1 focus-visible:outline-offset-2"
                   @click="open = !open"
                   :aria-expanded="open.toString()"
                   aria-controls="faq-panel-{{ loop.index }}">