feat: route /api/ping + message d'erreur affiche l'URL cible

- Ajout route GET /api/ping pour diagnostic connectivité rapide
- Le message 'serveur injoignable' affiche maintenant l'URL exacte tentée
- Aide à identifier les problèmes de proxy/iframe (mauvaise origine)

src/frontend/changelog.html

@@ -3,7 +3,7 @@
 <head>
 <meta charset="UTF-8">
 <meta name="viewport" content="width=device-width, initial-scale=1.0">
-<title>Changelog — imagod-web v0.2.0+build.24-0309359-dirty</title>
+<title>Changelog — imagod-web v0.2.0+build.25-41fcb23-dirty</title>
 <link rel="icon" href="data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 100 100'><text y='.9em' font-size='90'>🖼️</text></svg>">
 <style>
 * { margin:0; padding:0; box-sizing:border-box; }
@@ -37,7 +37,7 @@ footer { text-align:center; color:#484f58; font-size:0.8rem; padding:2rem; }
 </head>
 <body>
 <header>
-  <h1>📋 imagod-web <span class="version-badge">v0.2.0+build.24-0309359-dirty</span></h1>
+  <h1>📋 imagod-web <span class="version-badge">v0.2.0+build.25-41fcb23-dirty</span></h1>
   <nav>
     <a href="/">🖼️ Galerie</a>
     <a href="/changelog" class="active">📋 Changelog</a>
@@ -107,6 +107,6 @@ footer { text-align:center; color:#484f58; font-size:0.8rem; padding:2rem; }
 <h2>Légende des tags</h2>
 
 </main>
-<footer>imagod-web v0.2.0+build.24-0309359-dirty — <a href="https://git.dracodev.net/Projets/imagod-web">Gitea</a></footer>
+<footer>imagod-web v0.2.0+build.25-41fcb23-dirty — <a href="https://git.dracodev.net/Projets/imagod-web">Gitea</a></footer>
 </body>
 </html>

src/frontend/help.html

@@ -3,7 +3,7 @@
 <head>
 <meta charset="UTF-8">
 <meta name="viewport" content="width=device-width, initial-scale=1.0">
-<title>Aide & Roadmap — imagod-web v0.2.0+build.24-0309359-dirty</title>
+<title>Aide & Roadmap — imagod-web v0.2.0+build.25-41fcb23-dirty</title>
 <link rel="icon" href="data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 100 100'><text y='.9em' font-size='90'>🖼️</text></svg>">
 <style>
 * { margin:0; padding:0; box-sizing:border-box; }
@@ -37,7 +37,7 @@ footer { text-align:center; color:#484f58; font-size:0.8rem; padding:2rem; }
 </head>
 <body>
 <header>
-  <h1>❓ imagod-web <span class="version-badge">v0.2.0+build.24-0309359-dirty</span></h1>
+  <h1>❓ imagod-web <span class="version-badge">v0.2.0+build.25-41fcb23-dirty</span></h1>
   <nav>
     <a href="/">🖼️ Galerie</a>
     <a href="/changelog">📋 Changelog</a>
@@ -169,6 +169,6 @@ footer { text-align:center; color:#484f58; font-size:0.8rem; padding:2rem; }
 <p>5. <strong>Corriger le backend Imago</strong> (thumbnails, upload, stockage)</p>
 
 </main>
-<footer>imagod-web v0.2.0+build.24-0309359-dirty — <a href="https://git.dracodev.net/Projets/imagod-web">Gitea</a></footer>
+<footer>imagod-web v0.2.0+build.25-41fcb23-dirty — <a href="https://git.dracodev.net/Projets/imagod-web">Gitea</a></footer>
 </body>
 </html>

src/frontend/index.html

@@ -465,7 +465,7 @@
         <button class="btn" id="clear-btn" style="display:none">✕</button>
     </div>
     <button class="btn accent" id="header-upload-btn" onclick="document.getElementById('drop-zone').scrollIntoView({behavior:'smooth'}); document.getElementById('file-input').click()">📤 Upload</button>
-    <span class="version-badge" id="version-badge">v0.2.0+build.24-0309359-dirty</span>
+    <span class="version-badge" id="version-badge">v0.2.0+build.25-41fcb23-dirty</span>
 </div>
 
 <!-- ─── Navigation ─── -->
@@ -960,10 +960,10 @@ async function uploadFiles(files) {
             }
         } catch(e) {
             errorCount++;
-            // Distinguer les types d'erreurs réseau
             const msg = e.message || 'Erreur inconnue';
             if (msg.includes('Failed to fetch') || msg.includes('NetworkError')) {
-                showToast(`${file.name} : serveur injoignable — vérifiez la connexion`, 'error');
+                const apiUrl = window.location.origin + '/api/upload';
+                showToast(`${file.name} : serveur injoignable — essayez ${apiUrl}`, 'error');
             } else {
                 showToast(`${file.name} : ${msg}`, 'error');
             }

src/server/routes.rs

@@ -100,6 +100,7 @@ pub fn api_routes(state: AppState) -> Router {
     let state = Arc::new(state);
     Router::new()
         .route("/api/health", get(health_check))
+        .route("/api/ping", get(ping))
         .route("/api/auth/validate", post(validate_api_key))
         .route("/api/upload", post(upload_image))
         .route("/api/images", get(list_images))
@@ -119,6 +120,11 @@ async fn health_check() -> &'static str {
     "OK"
 }
 
+/// Test de connectivité minimal
+async fn ping() -> Json<serde_json::Value> {
+    Json(serde_json::json!({"pong": true, "timestamp": chrono::Utc::now().to_rfc3339()}))
+}
+
 /// Retourne la version de l'application et des infos utiles
 async fn version() -> Json<serde_json::Value> {
     Json(serde_json::json!({