feat: barre d'outils de lecture epinglee, coloration syntaxique des fichiers de code et avatars predefinis (#115, #117, BUG-078)

tests/frontend/unit.test.mjs

@@ -284,6 +284,28 @@ function testSidebarUserSection() {
   console.log('  ✓ header trimmed + sidebar account section (#112)');
 }
 
+// ── Test syntax highlighting follows the theme mode (BUG-078) ──────────────
+function testSyntaxHighlightTheme() {
+  const themes = readFileSync(join(JS_DIR, 'themes.js'), 'utf-8');
+  const ui = readFileSync(join(JS_DIR, 'ui.js'), 'utf-8');
+
+  // themes.js must swap the highlight.js stylesheets based on the *mode*.
+  const applyTheme = themes.match(/function applyTheme\(themeKey, mode\)\s*\{([\s\S]*?)\n\}/);
+  assert.ok(applyTheme, 'themes.js applyTheme not found');
+  assert.match(applyTheme[1], /hljs-theme-dark/, 'applyTheme must toggle the dark hljs sheet');
+  assert.match(applyTheme[1], /hljs-theme-light/, 'applyTheme must toggle the light hljs sheet');
+  assert.match(applyTheme[1], /mode === 'dark'|mode === "dark"/, 'sheet choice must key on the mode');
+
+  // ui.js must resolve the persisted *mode*, never treat the theme key as one.
+  assert.match(ui, /obsigate-theme-mode/, 'ui.js must read the persisted theme mode');
+  assert.doesNotMatch(
+    ui,
+    /darkSheet\.disabled\s*=\s*theme !== "dark"[\s\S]{0,120}lightSheet\.disabled\s*=\s*theme !== "light"/,
+    'ui.js must not compare the theme key to "dark"/"light" (BUG-078 regression)',
+  );
+  console.log('  ✓ syntax highlighting follows the theme mode (BUG-078)');
+}
+
 // ── Run all tests ──────────────────────────────────────────────────────────
 async function main() {
   let passed = 0, failed = 0;
@@ -300,6 +322,7 @@ async function main() {
     ['ai-fab module exports', testAIFabModuleExports],
     ['config TOC icons', testConfigTocIcons],
     ['sidebar user section', testSidebarUserSection],
+    ['syntax highlight theme', testSyntaxHighlightTheme],
   ];
 
   for (const [name, fn] of tests) {