chore: vendor all CDN assets locally; reorganise assets into css/ and js/

All third-party assets are now self-hosted — zero external requests at runtime.

CSS (assets/css/):
  - modern-normalize.min.css  (was assets/)
  - common.css, admin.css, main.css, search.css, tfe.css, apropos.css  (was assets/)
  - easymde.min.css 2.20.0  (was cdn.jsdelivr.net)
  - font-awesome.min.css 4.7.0  (was maxcdn.bootstrapcdn.com; injected at runtime by EasyMDE)

JS (assets/js/):
  - easymde.min.js 2.20.0  (was cdn.jsdelivr.net)

Fonts (assets/fonts/fontawesome/):
  - fontawesome-webfont.{eot,woff2,woff,ttf,svg}, FontAwesome.otf 4.7.0

Path fixes:
  - common.css @font-face: ./fonts/ -> ../fonts/ (one level deeper)
  - font-awesome.min.css @font-face: ../fonts/ -> ../fonts/fontawesome/ (dedicated subdir)
  - pages-edit.php: autoDownloadFontAwesome:false added to EasyMDE init to
    suppress the runtime CDN injection that was still present inside easymde.min.js

Reference updates (all now absolute /assets/css/* or /assets/js/*):
  - templates/public/head.php: modern-normalize + common
  - templates/admin/head.php: modern-normalize + admin
  - public/admin/login.php: modern-normalize + admin (standalone head)
  - public/index.php, tfe.php, search.php, apropos.php, licence.php: extraCss paths
  - public/admin/pages-edit.php: extraCss + extraJs (font-awesome, easymde CSS/JS)

Nginx static-file location already covers .css/.js/.woff/.woff2/.ttf/.otf with
30-day cache headers — no nginx config change needed.

public/assets/css/apropos.css

@@ -0,0 +1,187 @@
+/* ============================================================
+   À PROPOS PAGE (apropos.php) + LICENCE PAGE (licence.php)
+   ============================================================ */
+
+.apropos-body {
+  display: flex;
+  flex-direction: column;
+  min-height: 100vh;
+  background: var(--white);
+}
+
+.apropos-main {
+  flex: 1;
+  overflow-y: auto;
+  padding: 2.5rem 1.5rem 4rem;
+}
+
+/* Two-column layout */
+.apropos-layout {
+  display: grid;
+  grid-template-columns: 1.4fr 1fr;
+  gap: 4rem;
+  max-width: 1200px;
+}
+
+/* Single-column layout — used by licence.php (no right column) */
+.apropos-single {
+  max-width: 720px;
+}
+
+/* ------------------------------------------------------------------ */
+/* Main prose column — Markdown-rendered content                       */
+/* ------------------------------------------------------------------ */
+
+.prose {
+  font-family: "Courier New", Courier, monospace;
+  font-size: 1.55rem;
+  line-height: 1.45;
+  color: var(--black);
+  font-weight: 400;
+  margin: 0 0 2rem 0;
+}
+
+.prose p {
+  margin: 0 0 1.2em 0;
+}
+
+.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;
+}
+
+.apropos-section-title {
+  font-family: "Courier New", Courier, monospace;
+  font-size: 1.55rem;
+  font-weight: 400;
+  color: var(--black);
+  margin: 0 0 0.5rem 0;
+  line-height: 1.2;
+}
+
+.apropos-section-title a {
+  color: inherit;
+  text-decoration: underline;
+  text-underline-offset: 3px;
+}
+
+/* Contact entries — <address> elements */
+.apropos-aside address {
+  margin-bottom: 1rem;
+  font-style: normal; /* override browser italic default for <address> */
+}
+
+.apropos-aside address strong {
+  font-weight: 700;
+  font-size: 0.95rem;
+  color: var(--black);
+  display: block;
+  margin-bottom: 0.15rem;
+}
+
+.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;
+}
+
+/* Licences section (legacy) */
+.apropos-licences {
+  margin-top: 2rem;
+}
+
+.apropos-licences h2 {
+  font-family: "Courier New", Courier, monospace;
+  font-size: 1.55rem;
+  font-weight: 400;
+  margin: 0 0 0.75rem 0;
+}
+
+.apropos-licences p {
+  font-size: 0.9rem;
+  color: var(--black);
+  line-height: 1.6;
+  margin: 0 0 0.75rem 0;
+}
+
+/* Responsive */
+@media (max-width: 900px) {
+  .apropos-layout {
+    grid-template-columns: 1fr;
+    gap: 2rem;
+  }
+
+  .prose {
+    font-size: 1.2rem;
+  }
+
+  .apropos-section-title {
+    font-size: 1.2rem;
+  }
+}
+
+@media (max-width: 600px) {
+  .apropos-main {
+    padding: 1.5rem 1rem 3rem;
+  }
+
+  .prose {
+    font-size: 1rem;
+  }
+}