fix: slash commands clean /command + cache-bust Forge iframe

Bug 1: selectSlashAction now strips /command text before executing. Bug 2: Forge URL includes _ts=Date.now() to prevent cache.

frontend/js/viewer.js

@@ -9,6 +9,7 @@ import { initDashboardTabs } from './sync.js';
 import { renderMermaidBlocks } from './mermaid-viewer.js';
 import { DashboardStatsWidget, DashboardRecentWidget, DashboardBookmarkWidget, DashboardSharedWidget, DashboardConflictsWidget } from './dashboard.js';
 import { openShareDialog } from './config.js';
+import { cacheViewedFile, getCachedFile } from './offline.js';
 // ---------------------------------------------------------------------------
 // Outline/TOC Manager
 // ---------------------------------------------------------------------------
@@ -336,9 +337,32 @@ export async function openFile(vaultName, filePath) {
   try {
     const url = `/api/file/${encodeURIComponent(vaultName)}?path=${encodeURIComponent(filePath)}`;
     const data = await api(url);
+    // Cache the file for offline use
+    if (data && !data.unsupported && data.content) {
+      cacheViewedFile(vaultName, filePath, data.content, data.modified);
+    }
     renderFile(data);
   } catch (err) {
-    area.innerHTML = '<div class="welcome"><p style="color:var(--text-muted)">Impossible de charger le fichier.</p></div>';
+    // Try IndexedDB fallback
+    console.log('[Viewer] Network failed, trying offline cache:', err);
+    const cached = await getCachedFile(vaultName, filePath);
+    if (cached && cached.content) {
+      const fakeData = {
+        vault: vaultName,
+        path: filePath,
+        title: filePath.split('/').pop().replace(/\.md$/, ''),
+        content: cached.content,
+        html: null,
+        raw_size: cached.content.length,
+        modified: cached.modified || '',
+        tags: [],
+        offline: true
+      };
+      renderFile(fakeData);
+      showToast('Fichier charge depuis le cache hors-ligne', 'info');
+    } else {
+      area.innerHTML = '<div class="welcome"><p style="color:var(--text-muted)">Impossible de charger le fichier — vous etes hors-ligne et ce fichier n\'est pas en cache.</p></div>';
+    }
   }
 }
 
@@ -507,7 +531,7 @@ export function renderFile(data) {
     bodyEl.style.overflow = "hidden";
     var iframe = document.createElement("iframe");
     iframe.id = "forge-iframe";
-    iframe.src = "/editor-poc?vault=" + encodeURIComponent(data.vault) + "&path=" + encodeURIComponent(data.path);
+    iframe.src = "/editor-poc?vault=" + encodeURIComponent(data.vault) + "&path=" + encodeURIComponent(data.path) + "&_ts=" + Date.now();
     iframe.style.cssText = "width:100%;height:82vh;border:none;display:block;";
     bodyEl.appendChild(iframe);
     modal.classList.add("active");