Fix typos blanches admin lightmode + hero audience

- Remplace color:white → hsl(var(--color-text)) dans tous les composants admin
  (AdminFieldText, AdminFieldTextarea, AdminFormSection, AdminMarkdownEditor,
  AdminMediaBrowser, AdminSidebar, book/index, book/[slug], login, messages, site, songs)
- Conserve color:white uniquement sur fond primary (AdminSaveButton, login-btn)
- Hero home : ajout bloc audience/addressees (clé distincte pour éviter conflit YAML)
- home.yml : réordonne axes (citoyenne en premier — effet triangle)
- TypewriterText : affiche le second bloc avec séparateur fin

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/components/admin/AdminFieldText.vue

@@ -44,7 +44,7 @@ const id = computed(() => `field-${props.label.toLowerCase().replace(/\s+/g, '-'
   border-radius: 0.5rem;
   border: 1px solid hsl(var(--color-surface-light));
   background: hsl(var(--color-bg));
-  color: white;
+  color: hsl(var(--color-text));
   font-size: 0.875rem;
   transition: border-color 0.2s;
 }

app/components/admin/AdminFieldTextarea.vue

@@ -45,7 +45,7 @@ const id = computed(() => `field-${props.label.toLowerCase().replace(/\s+/g, '-'
   border-radius: 0.5rem;
   border: 1px solid hsl(var(--color-surface-light));
   background: hsl(var(--color-bg));
-  color: white;
+  color: hsl(var(--color-text));
   font-size: 0.875rem;
   resize: vertical;
   min-height: 5rem;

app/components/admin/AdminFormSection.vue

@@ -32,7 +32,7 @@ defineProps<{
   padding: 0.75rem 1rem;
   font-weight: 600;
   font-size: 0.9rem;
-  color: white;
+  color: hsl(var(--color-text));
   cursor: pointer;
   background: hsl(var(--color-bg));
   user-select: none;

app/components/admin/AdminMarkdownEditor.vue

@@ -129,7 +129,7 @@ const renderedHtml = computed(() => {
 }
 
 .md-tab--active {
-  color: white;
+  color: hsl(var(--color-text));
   background: hsl(var(--color-surface));
 }
 
@@ -139,7 +139,7 @@ const renderedHtml = computed(() => {
   transition: color 0.2s;
 }
 .md-fullscreen:hover,
-.md-fullscreen--active { color: white; }
+.md-fullscreen--active { color: hsl(var(--color-text)); }
 
 .md-body {
   display: flex;
@@ -171,7 +171,7 @@ const renderedHtml = computed(() => {
   padding: 1rem;
   border: none;
   background: hsl(var(--color-bg));
-  color: white;
+  color: hsl(var(--color-text));
   font-family: var(--font-mono, monospace);
   font-size: 0.85rem;
   line-height: 1.7;

app/components/admin/AdminMediaBrowser.vue

@@ -169,7 +169,7 @@ function formatSize(bytes: number): string {
 
 .media-name {
   font-size: 0.72rem;
-  color: white;
+  color: hsl(var(--color-text));
   white-space: nowrap;
   overflow: hidden;
   text-overflow: ellipsis;

app/components/admin/AdminSidebar.vue

@@ -139,7 +139,7 @@ async function logout() {
 
 .sidebar-link:hover {
   background: hsl(var(--color-surface));
-  color: white;
+  color: hsl(var(--color-text));
 }
 
 .sidebar-link--active {