refactor(ui): modernize button + input border radii (rounded-lg/md/xl, sharper SaaS aesthetic)

Aligns DictIA marketing/auth/legal/billing templates with modern SaaS visual
conventions (Linear, Vercel, Stripe Dashboard, Notion). Old radii (12-18px)
felt dated; new system uses 6-12px for tighter, more contemporary corners.

Border radius system:
- Buttons (CTA, submit, secondary): rounded-[0.75rem] (12px) -> rounded-lg (8px)
- Form inputs (text/email/password/select/textarea/checkbox): rounded-[0.5rem] -> rounded-md (6px)
- Cards (pricing, bento, modals, content panels): rounded-[18px]/[14px]/[12px] -> rounded-xl (12px)
- Pricing card outer gradient frame: rounded-[20px] -> rounded-xl (matches inner)
- Pills / badges / status chips: KEEP rounded-full
- Avatars / circular icon containers: KEEP rounded-full
- Code blocks: KEEP rounded (4px)

Decision tree applied for ambiguous cases:
- Button-like clickable CTA -> rounded-lg
- Form input -> rounded-md
- Card / panel / modal -> rounded-xl
- Badge / pill / chip / avatar -> rounded-full (preserved)

In-scope templates modified (23):
- macros/button.html (central macro, cascades to all callers)
- macros/pricing_card.html, macros/bento.html
- marketing/landing.html, tarifs.html, fonctionnalites.html, conformite.html, contact.html
- auth/check_email.html, forgot_password.html, magic_link_request.html, oauth_finish_signup.html,
  passkey_setup.html, reset_password.html, totp_setup.html, totp_verify.html, verify_success.html
- billing/cancel.html, billing/success.html
- legal/_layout.html, legal/index.html
- register.html, login.html

Out of scope (untouched): index.html, account.html, admin.html, share.html, inquire.html,
group-admin.html, components/**, includes/**, modals/** (all legacy Speakr Vue surfaces).

Tests: test_marketing_landing_template.py — 2 assertions updated to match new bento icon
(rounded-md) and pricing card frame (rounded-xl). All 18 legal tests + 58 marketing landing
tests + 9 signup_loi25 tests still pass. Decorative rounded-full preserved on hero cosmic
orbs and ordres-pros avatar circles.

Diff: 94 insertions / 94 deletions (1:1 mechanical replacement, no class drift).

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

templates/marketing/fonctionnalites.html

@@ -25,7 +25,7 @@
     {# 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-[18px] overflow-hidden">
+    <div class="grid grid-cols-1 sm:grid-cols-2 md:grid-cols-3 gap-[1.5px] bg-brand-border rounded-xl 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.', '📝') }}
@@ -55,7 +55,7 @@
         {'ext': 'JSON', 'use': 'Pipeline développeur'},
         {'ext': 'MD',   'use': 'Notion, Obsidian, GitHub'}
       ] %}
-      <div class="bg-white p-4 rounded-[12px] border border-brand-border text-center">
+      <div class="bg-white p-4 rounded-xl border border-brand-border text-center">
         <p class="text-base font-black text-brand-navy">{{ fmt.ext }}</p>
         <p class="text-xs text-brand-navy/70 mt-1">{{ fmt.use | safe }}</p>
       </div>
@@ -87,7 +87,7 @@
         {'name': 'Make (Integromat)', 'desc': 'Scénarios visuels'},
         {'name': 'n8n', 'desc': 'Open source self-host'}
       ] %}
-      <div class="bg-brand-bg p-5 rounded-[14px] border border-brand-border text-center">
+      <div class="bg-brand-bg p-5 rounded-xl border border-brand-border text-center">
         <p class="text-base font-bold text-brand-navy">{{ integ.name | safe }}</p>
         <p class="text-xs text-brand-navy/70 mt-1">{{ integ.desc | safe }}</p>
       </div>
@@ -117,7 +117,7 @@
         {'title': 'Audio supportés', 'desc': 'WAV, MP3, M4A, FLAC, OGG, WebM — jusqu\'à 8&nbsp;h par fichier. Conversion ffmpeg automatique.'},
         {'title': 'Langues', 'desc': 'Optimisé français québécois. Aussi&nbsp;: français de France, anglais (canadien et US), espagnol, allemand, mandarin, russe.'}
       ] %}
-      <article class="bg-white/[0.05] backdrop-blur-sm p-6 rounded-[0.75rem] border border-white/[0.08]">
+      <article class="bg-white/[0.05] backdrop-blur-sm p-6 rounded-lg border border-white/[0.08]">
         <h3 class="text-lg font-bold mb-2 text-white">{{ spec.title | safe }}</h3>
         <p class="text-sm text-white/80 leading-relaxed">{{ spec.desc | safe }}</p>
       </article>