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/auth/totp_verify.html

@@ -5,7 +5,7 @@
 
 {% block content %}
 <section class="min-h-[calc(100vh-62px)] bg-brand-bg py-16 px-4" aria-labelledby="totp-verify-title">
-  <div class="max-w-md mx-auto bg-white p-8 rounded-xl border border-brand-border shadow-cta">
+  <div class="max-w-md mx-auto bg-white p-8 rounded-lg border border-brand-border shadow-cta">
     <h1 id="totp-verify-title" class="text-3xl font-black text-brand-navy mb-2">Vérification en deux étapes</h1>
     <p class="text-sm text-brand-navy/70 mb-6">Entrez le code à 6 chiffres affiché dans votre application authenticator pour terminer la connexion.</p>
 
@@ -31,7 +31,7 @@
     {% if has_passkeys %}
     <section class="mb-6" aria-labelledby="passkey-section-title">
       <h2 id="passkey-section-title" class="text-base font-semibold text-brand-navy mb-3">Connexion par Passkey</h2>
-      <button id="passkey-auth-btn" type="button" 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">
+      <button id="passkey-auth-btn" type="button" class="w-full grad-bg text-white font-semibold py-3 rounded shadow-cta hover:shadow-cta-hover transition focus-visible:outline-2 focus-visible:outline-brand-b1 focus-visible:outline-offset-2">
         Utiliser ma Passkey
       </button>
       <p id="passkey-status" class="text-xs text-brand-navy/70 mt-2" role="status" aria-live="polite"></p>
@@ -54,11 +54,11 @@
         <input type="text" id="code" name="code"
                inputmode="numeric" autocomplete="one-time-code"
                pattern="[0-9]{6}" maxlength="6"
-               class="w-full px-3 py-3 border border-brand-border rounded-md text-brand-navy text-center text-2xl font-mono tracking-widest focus-visible:outline-2 focus-visible:outline-brand-b1 focus-visible:outline-offset-2"
+               class="w-full px-3 py-3 border border-brand-border rounded text-brand-navy text-center text-2xl font-mono tracking-widest focus-visible:outline-2 focus-visible:outline-brand-b1 focus-visible:outline-offset-2"
                placeholder="000000" autofocus>
       </div>
 
-      <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">
+      <button type="submit" class="w-full grad-bg text-white font-semibold py-3 rounded shadow-cta hover:shadow-cta-hover transition focus-visible:outline-2 focus-visible:outline-brand-b1 focus-visible:outline-offset-2">
         Vérifier et se connecter
       </button>
     </form>
@@ -74,11 +74,11 @@
           <label for="recovery_code" class="block text-sm font-medium text-brand-navy mb-1">Code de récupération <span class="text-red-600" aria-hidden="true">*</span></label>
           <input type="text" id="recovery_code" name="recovery_code"
                  autocomplete="off"
-                 class="w-full px-3 py-2 border border-brand-border rounded-md text-brand-navy font-mono uppercase 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 text-brand-navy font-mono uppercase focus-visible:outline-2 focus-visible:outline-brand-b1 focus-visible:outline-offset-2"
                  placeholder="XXXXX-XXXXX">
           <p class="text-xs text-brand-navy/60 mt-1">Format&nbsp;: 5 caractères + tiret + 5 caractères. Chaque code est à usage unique.</p>
         </div>
-        <button type="submit" class="w-full bg-brand-navy text-white font-semibold py-3 rounded-lg hover:bg-brand-navy2 transition focus-visible:outline-2 focus-visible:outline-brand-b1 focus-visible:outline-offset-2">
+        <button type="submit" class="w-full bg-brand-navy text-white font-semibold py-3 rounded hover:bg-brand-navy2 transition focus-visible:outline-2 focus-visible:outline-brand-b1 focus-visible:outline-offset-2">
           Utiliser le code de récupération
         </button>
         <p class="text-xs text-brand-navy/60 text-center" aria-live="polite">{{ recovery_codes_remaining }} code{{ 's' if recovery_codes_remaining != 1 else '' }} de récupération restant{{ 's' if recovery_codes_remaining != 1 else '' }}.</p>