semantic HTML: apropos.php and licence.php (TODO section V & VI)

apropos.php:
- Remove redundant <div class="apropos-left"> wrapper; prose div is now a direct
  grid child
- <div class="apropos-description apropos-page-content"> → <div class="prose">
  (single canonical class for Markdown-rendered content)
- <div class="apropos-right"> → <aside class="apropos-aside"> (supplementary info
  landmark; contacts and credits are secondary to the main description)
- Three bare <div> wrappers inside the aside → <section> (erg link, Contacts, Crédits)
- Three <div class="apropos-contact"> entries → <address> with font-style:normal
  override; <span class="apropos-contact-name"> → <strong>;
  <span class="apropos-contact-email"> → <a href="mailto:…">
  Removes classes: apropos-left, apropos-right, apropos-contact, apropos-contact-name,
  apropos-contact-role, apropos-contact-email, apropos-description, apropos-page-content

licence.php:
- <div class="apropos-description apropos-page-content apropos-single"> →
  <div class="prose apropos-single"> (consistent with apropos.php rename)

apropos.css:
- Rename .apropos-description / .apropos-page-content → .prose; merge all prose
  content rules under the single .prose selector
- Rename .apropos-right → .apropos-aside; remove .apropos-left (empty rule)
- Replace .apropos-contact, .apropos-contact-name etc. with element selectors:
  .apropos-aside address, .apropos-aside address strong,
  .apropos-aside address span, .apropos-aside address a
- Update responsive blocks to reference .prose instead of .apropos-description

public/assets/apropos.css

@@ -1,5 +1,5 @@
 /* ============================================================
-   À PROPOS PAGE (apropos.php)
+   À PROPOS PAGE (apropos.php) + LICENCE PAGE (licence.php)
    ============================================================ */
 
 .apropos-body {
@@ -28,10 +28,11 @@
   max-width: 720px;
 }
 
-/* Left col — main description text in big monospace */
-.apropos-left {}
+/* ------------------------------------------------------------------ */
+/* Main prose column — Markdown-rendered content                       */
+/* ------------------------------------------------------------------ */
 
-.apropos-description {
+.prose {
   font-family: "Courier New", Courier, monospace;
   font-size: 1.55rem;
   line-height: 1.45;
@@ -40,12 +41,53 @@
   margin: 0 0 2rem 0;
 }
 
-.apropos-description p {
+.prose p {
   margin: 0 0 1.2em 0;
 }
 
-/* Right col — links, contacts, credits */
-.apropos-right {
+.prose h1,
+.prose h2,
+.prose h3 {
+  font-family: "Courier New", Courier, monospace;
+  font-weight: 400;
+  margin: 1.5em 0 0.5em 0;
+}
+
+.prose h1 { font-size: 1.55rem; }
+.prose h2 { font-size: 1.3rem; }
+.prose h3 { font-size: 1.1rem; }
+
+.prose a {
+  color: var(--purple);
+  text-underline-offset: 2px;
+}
+
+.prose ul,
+.prose ol {
+  padding-left: 1.5rem;
+  margin-bottom: 1rem;
+}
+
+.prose li {
+  margin-bottom: .3em;
+}
+
+.prose strong { font-weight: 700; }
+.prose em { font-style: italic; }
+
+.prose code {
+  font-family: "Courier New", Courier, monospace;
+  font-size: 0.9em;
+  background: rgba(0,0,0,.06);
+  padding: .1em .3em;
+  border-radius: 2px;
+}
+
+/* ------------------------------------------------------------------ */
+/* Right aside — links, contacts, credits                              */
+/* ------------------------------------------------------------------ */
+
+.apropos-aside {
   display: flex;
   flex-direction: column;
   gap: 2rem;
@@ -66,11 +108,13 @@
   text-underline-offset: 3px;
 }
 
-.apropos-contact {
+/* Contact entries — <address> elements */
+.apropos-aside address {
   margin-bottom: 1rem;
+  font-style: normal; /* override browser italic default for <address> */
 }
 
-.apropos-contact-name {
+.apropos-aside address strong {
   font-weight: 700;
   font-size: 0.95rem;
   color: var(--black);
@@ -78,57 +122,26 @@
   margin-bottom: 0.15rem;
 }
 
-.apropos-contact-role,
-.apropos-contact-email {
+.apropos-aside address span,
+.apropos-aside address a {
   font-size: 0.9rem;
   color: var(--black);
   line-height: 1.4;
   display: block;
 }
 
+.apropos-aside address a {
+  text-decoration: underline;
+  text-underline-offset: 2px;
+}
+
 .apropos-credits-text {
   font-size: 0.9rem;
   color: var(--black);
   line-height: 1.6;
 }
 
-/* Markdown-rendered page content */
-.apropos-page-content p {
-  margin: 0 0 1.2em 0;
-}
-.apropos-page-content h1,
-.apropos-page-content h2,
-.apropos-page-content h3 {
-  font-family: "Courier New", Courier, monospace;
-  font-weight: 400;
-  margin: 1.5em 0 0.5em 0;
-}
-.apropos-page-content h1 { font-size: 1.55rem; }
-.apropos-page-content h2 { font-size: 1.3rem; }
-.apropos-page-content h3 { font-size: 1.1rem; }
-.apropos-page-content a {
-  color: var(--purple);
-  text-underline-offset: 2px;
-}
-.apropos-page-content ul,
-.apropos-page-content ol {
-  padding-left: 1.5rem;
-  margin-bottom: 1rem;
-}
-.apropos-page-content li {
-  margin-bottom: .3em;
-}
-.apropos-page-content strong { font-weight: 700; }
-.apropos-page-content em { font-style: italic; }
-.apropos-page-content code {
-  font-family: "Courier New", Courier, monospace;
-  font-size: 0.9em;
-  background: rgba(0,0,0,.06);
-  padding: .1em .3em;
-  border-radius: 2px;
-}
-
-/* Licences section */
+/* Licences section (legacy) */
 .apropos-licences {
   margin-top: 2rem;
 }
@@ -154,7 +167,7 @@
     gap: 2rem;
   }
 
-  .apropos-description {
+  .prose {
     font-size: 1.2rem;
   }
 
@@ -168,7 +181,7 @@
     padding: 1.5rem 1rem 3rem;
   }
 
-  .apropos-description {
+  .prose {
     font-size: 1rem;
   }
 }