refactor(ui): V3 fully square buttons + inputs (rounded-none, brutalist/Swiss aesthetic)

V3 finalizes the radii pass to a fully brutalist/Swiss visual language:

- Buttons (CTAs, submit, secondary, ghost, OAuth provider tiles): rounded-none (0px)
- Form inputs (text/email/password/select/textarea/code-entry): rounded-none (0px)
- Checkboxes: rounded-none (0px) — was rounded-sm
- Small icon tiles (w-10 h-10 / w-12 h-12 grad-bg squares): rounded-none (0px)
- Inline code blocks (totp recovery <pre>, secret <code>): rounded-none (0px)
- Cards (pricing, bento, content panels, modals, prev/next nav): rounded (4px) — was rounded-lg
- Alert / flash boxes: rounded (4px) — was rounded-lg
- Pills, badges, status chips, ordres pros avatars, decorative cosmic orbs: rounded-full preserved
- Legal _layout.html inline <style> blockquote/pre/code/draft-callout: border-radius 0 — was 4px

Updated tests/test_marketing_landing_template.py assertions:
- bento icon assertion: "grad-bg rounded " -> "grad-bg rounded-none "
- pricing recommended frame: "rounded-lg" -> "rounded" (with strict trailing-char match to avoid rounded-none false positive)

Verification: 18/18 legal tests pass, 58/58 marketing landing tests pass, 5/5 root redirect tests pass. Two pre-existing failures in test_marketing_secondary_pages (SOC 2 hedge text + gitea.innova-ai.ca URL) are unrelated to this radii pass.

templates/marketing/tarifs.html

@@ -36,7 +36,7 @@
       </h2>
     </div>
 
-    <div class="overflow-x-auto rounded-lg border border-brand-border">
+    <div class="overflow-x-auto rounded border border-brand-border">
       <table class="w-full min-w-[720px] text-sm">
         <caption class="sr-only">Comparaison détaillée des 3 forfaits DictIA sur 8 caractéristiques</caption>
         <thead class="bg-brand-bg">
@@ -94,7 +94,7 @@
       <div x-data="{ open: false }" class="py-2">
         <h3>
           <button type="button"
-                  class="w-full flex items-center justify-between gap-4 py-4 text-left hover:bg-brand-navy/[0.03] transition-colors rounded 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-navy/[0.03] transition-colors rounded-none 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="tarifs-faq-panel-{{ loop.index }}">