perf & ux : cache getAll, fingerprint assets, Last-Modified, 404 log, row-click bulk (v1.6.19)

- getAll() : cache fichier articles_list.json, invalidé à chaque écriture (#16)
- layout.php : fingerprinting ?v=<hash> sur CSS/JS pour invalidation navigateur (#18)
- case 'view' : Last-Modified + 304 Not Modified pour les articles publiés (#18)
- case 'not_found' : logging JSON des 404 dans _logs/not_found.jsonl (#52)
- case 'view' : echo nu → templates/404.php pour brouillons/privés (#52)
- admin.js : clic sur ligne tableau → toggle bulk-check (#86)

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

templates/layout.php

@@ -46,11 +46,20 @@
 
     <!-- CSS -->
     <link href="/assets/css/bootstrap.min.css" rel="stylesheet">
-    <link rel="stylesheet" href="/assets/css/style.css">
+    <?php
+    $_pub = BASE_PATH . '/public/assets/';
+    if (!function_exists('_av')) {
+        function _av(string $base, string $rel): string {
+            $f = $base . $rel;
+            return '/assets/' . $rel . (is_file($f) ? '?v=' . substr(md5_file($f), 0, 8) : '');
+        }
+    }
+    ?>
+    <link rel="stylesheet" href="<?= _av($_pub, 'css/style.css') ?>">
 </head>
 
 <body<?php if (!empty($bodyClass ?? '')): ?> class="<?= htmlspecialchars($bodyClass) ?>"<?php endif; ?>>
-<script src="/assets/js/density-fouc.js"></script>
+<script src="<?= _av($_pub, 'js/density-fouc.js') ?>"></script>
 
 <header>
     <nav class="navbar navbar-expand-lg navbar-dark mb-0" role="navigation" aria-label="Navigation principale">
@@ -150,9 +159,9 @@ $_layoutCurrentCat = trim($_GET['cat'] ?? '');
 
 <!-- JS -->
 <script src="/assets/js/bootstrap.bundle.min.js"></script>
-<script src="/assets/js/app.js"></script>
+<script src="<?= _av($_pub, 'js/app.js') ?>"></script>
 <?php if (isset($reactionStats)): ?>
-<script src="/assets/js/reactions.js"></script>
+<script src="<?= _av($_pub, 'js/reactions.js') ?>"></script>
 <?php endif; ?>
 
 </body>