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/auth/reset_password.html

@@ -5,7 +5,7 @@
 
 {% block content %}
 <section class="min-h-[calc(100vh-62px)] bg-brand-bg py-16 px-4" aria-labelledby="reset-title">
-  <div class="max-w-md mx-auto bg-white p-8 rounded-[18px] border border-brand-border shadow-cta">
+  <div class="max-w-md mx-auto bg-white p-8 rounded-xl border border-brand-border shadow-cta">
     <h1 id="reset-title" class="text-3xl font-black text-brand-navy mb-2">Nouveau mot de passe</h1>
     <p class="text-sm text-brand-navy/70 mb-6">Choisissez un mot de passe robuste pour sécuriser votre compte DictIA.</p>
 
@@ -29,7 +29,7 @@
       <div>
         <label for="password" class="block text-sm font-medium text-brand-navy mb-1">Nouveau mot de passe <span class="text-red-600" aria-hidden="true">*</span></label>
         <input type="password" id="password" name="password" autocomplete="new-password" minlength="8" required aria-required="true" aria-describedby="password-help"
-               class="w-full px-3 py-2 border border-brand-border rounded-[0.5rem] text-brand-navy focus-visible:outline-2 focus-visible:outline-brand-b1 focus-visible:outline-offset-2"
+               class="w-full px-3 py-2 border border-brand-border rounded-md text-brand-navy focus-visible:outline-2 focus-visible:outline-brand-b1 focus-visible:outline-offset-2"
                placeholder="••••••••">
         <p id="password-help" class="text-xs text-brand-navy/70 mt-1">{{ "8&nbsp;caractères minimum, dont une majuscule, une minuscule, un chiffre et un caractère spécial." | safe }}</p>
       </div>
@@ -37,11 +37,11 @@
       <div>
         <label for="confirm_password" class="block text-sm font-medium text-brand-navy mb-1">Confirmer le mot de passe <span class="text-red-600" aria-hidden="true">*</span></label>
         <input type="password" id="confirm_password" name="confirm_password" autocomplete="new-password" minlength="8" required aria-required="true"
-               class="w-full px-3 py-2 border border-brand-border rounded-[0.5rem] text-brand-navy focus-visible:outline-2 focus-visible:outline-brand-b1 focus-visible:outline-offset-2"
+               class="w-full px-3 py-2 border border-brand-border rounded-md text-brand-navy focus-visible:outline-2 focus-visible:outline-brand-b1 focus-visible:outline-offset-2"
                placeholder="••••••••">
       </div>
 
-      <button type="submit" class="w-full grad-bg text-white font-semibold py-3 rounded-[0.75rem] shadow-cta hover:shadow-cta-hover transition focus-visible:outline-2 focus-visible:outline-brand-b1 focus-visible:outline-offset-2">
+      <button type="submit" class="w-full grad-bg text-white font-semibold py-3 rounded-lg shadow-cta hover:shadow-cta-hover transition focus-visible:outline-2 focus-visible:outline-brand-b1 focus-visible:outline-offset-2">
         Définir mon nouveau mot de passe
       </button>
     </form>