newOS4 v4.6.35: file manager multi-select + safe paste/rename/delete (Part B)

4 files changed, 324 insertions, 166 deletions

diff --git a/main.html b/main.html
index 607e1f0..37b2a01 100644
--- a/main.html
+++ b/main.html
@@ -1349,13 +1349,13 @@
     </script>
 
     <!-- v4.5.63: A2A scratchpad fixes + agent-register arg fix -->
-<script src="modules/core/core-bundle.js?v=v4.6.34"></script>
+<script src="modules/core/core-bundle.js?v=v4.6.35"></script>
 
     <!-- Async dependency-ordered module loader now only initializes terminal and loads optional ext modules -->
-<script src="modules/core/module-loader.js?v=v4.6.34"></script>
+<script src="modules/core/module-loader.js?v=v4.6.35"></script>
 
     <!-- Critical ext bundle loads AFTER webx11 exists so registerModule calls work -->
-<script src="modules/ext/critical-ext-bundle.js?v=v4.6.34"></script>
+<script src="modules/ext/critical-ext-bundle.js?v=v4.6.35"></script>
 
 <script>
 // ═══ ONE TRUE VERSION SOURCE ═══
diff --git a/modules/core/module-loader.js b/modules/core/module-loader.js
index 2bfc0ec..3a85417 100644
--- a/modules/core/module-loader.js
+++ b/modules/core/module-loader.js
@@ -4,7 +4,7 @@
     // Core module bundle loaded synchronously in main.html.
     // This loader only handles version cache-busting, splash, terminal init, and optional ext modules.
 
-    const LATEST_VER = 'v4.6.34';
+    const LATEST_VER = 'v4.6.35';
     const CACHE = '?v=' + LATEST_VER;
     const stored = localStorage.getItem('webx11_cache_ver');
     if (stored !== LATEST_VER) {
diff --git a/modules/ext/critical-ext-bundle.js b/modules/ext/critical-ext-bundle.js
index 8773f47..504dfa8 100644
--- a/modules/ext/critical-ext-bundle.js
+++ b/modules/ext/critical-ext-bundle.js
@@ -942,6 +942,8 @@ class FileManagerModule {
         this._overlay = null;
         this._selectedFile = null;
         this._multiSelect = new Set();  // v4.5.78: multi-select for batch ops
+        this._selectMode = false;       // v4.6.35: tap-to-select mode (touch devices)
+        this._itemCount = 0;            // items rendered in the current directory/filter
         this._clipboard = { mode: null, paths: [] };  // 'copy' or 'cut'
         this._searchFilter = '';
         this._rawMode = false;
@@ -1359,6 +1361,15 @@ class FileManagerModule {
         batchBar.appendChild(mkBtn('🗑️ Del', 'Delete selected files', () => this._batchDelete()));
         batchBar.appendChild(mkBtn('📝 Rename', 'Rename selected file', () => this._batchRename()));
         batchBar.appendChild(mkBtn('☐ All', 'Toggle select all', () => this._toggleSelectAll()));
+        // v4.6.35: tap-to-select mode — the only usable multi-select path on touch devices
+        const selModeBtn = mkBtn('☑ Select', 'Toggle tap-to-select mode (touch)', () => {
+            this._selectMode = !this._selectMode;
+            selModeBtn.style.background = this._selectMode ? 'var(--accent-color)' : 'none';
+            selModeBtn.style.color = this._selectMode ? '#fff' : 'var(--text-color)';
+            this._updateStatus(this._selectMode ? 'Select mode ON — tap rows to select' : 'Select mode OFF');
+        });
+        selModeBtn.setAttribute('aria-pressed', 'false');
+        batchBar.appendChild(selModeBtn);
         toolbar.appendChild(batchBar);
 
         overlay.appendChild(toolbar);
@@ -1460,6 +1471,9 @@ class FileManagerModule {
         if (this._overlay) {
             this._overlay.style.display = 'none';
         }
+        this._multiSelect.clear();
+        this._selectedFile = null;
+        this._selectMode = false;
     }
 
     _clearOverlay() {
@@ -1468,6 +1482,8 @@ class FileManagerModule {
         }
         this._overlay = null;
         this._selectedFile = null;
+        this._multiSelect.clear();
+        this._selectMode = false;
         this._searchFilter = '';
         this._rawMode = false;
     }
@@ -1475,6 +1491,7 @@ class FileManagerModule {
     _navigateTo(pathParts) {
         this.currentPath = pathParts || [];
         this._selectedFile = null;
+        this._multiSelect.clear();
         this._searchFilter = '';
         const searchInput = this._overlay?.querySelector('input[type="text"]');
         if (searchInput) searchInput.value = '';
@@ -1527,6 +1544,13 @@ class FileManagerModule {
         const dirs = entries.filter(e => e.type === 'dir');
         const files = entries.filter(e => e.type !== 'dir');
 
+        // Prune selections that no longer exist here (deleted/moved elsewhere)
+        try {
+            const _live = new Set();
+            entries.forEach(e => _live.add(pathStr === '/' ? '/' + e.name : pathStr + '/' + e.name));
+            [...this._multiSelect].forEach(p => { if (!_live.has(p)) this._multiSelect.delete(p); });
+        } catch (_e) {}
+
         // Sort alphabetically
         dirs.sort((a, b) => a.name.localeCompare(b.name));
         files.sort((a, b) => a.name.localeCompare(b.name));
@@ -1540,6 +1564,7 @@ class FileManagerModule {
             filteredFiles = files.filter(e => e.name.toLowerCase().includes(q));
         }
 
+        const _scrollTop = sidebar.scrollTop;
         sidebar.innerHTML = '';
 
         if (filteredDirs.length === 0 && filteredFiles.length === 0) {
@@ -1547,7 +1572,8 @@ class FileManagerModule {
             emptyMsg.style.cssText = 'padding:20px;text-align:center;color:var(--text-muted);';
             emptyMsg.textContent = this._searchFilter ? 'No matching files' : '(empty)';
             sidebar.appendChild(emptyMsg);
-            this._updateStatus('0 files');
+            this._itemCount = 0;
+            this._updateSelectionStatus();
             return;
         }
 
@@ -1557,14 +1583,17 @@ class FileManagerModule {
             const fullPath = pathStr === '/' ? '/' + entry.name : pathStr + '/' + entry.name;
             item.dataset.path = fullPath;
             item.dataset.type = 'dir';
-            item.style.cssText = 'display:flex;align-items:center;padding:6px 10px;cursor:pointer;border-bottom:1px solid var(--border-color);gap:6px;';
+            item.style.cssText = 'display:flex;align-items:center;padding:6px 10px;cursor:pointer;border-bottom:1px solid var(--border-color);gap:6px;border-left:3px solid transparent;';
             item.onmouseenter = () => { if (!item.dataset.selected) item.style.background = 'var(--bg-tertiary)'; };
             item.onmouseleave = () => { if (!item.dataset.selected) item.style.background = 'transparent'; };
-            item.onclick = () => {
+            item.onclick = (e) => {
+                if (e.ctrlKey || e.metaKey || this._selectMode) { e.preventDefault(); this._toggleMulti(fullPath); return; }
                 const newPath = [...this.currentPath, entry.name];
                 this._navigateTo(newPath);
             };
 
+            item.appendChild(this._makeCheckbox(fullPath, entry.name + '/'));
+
             const icon = document.createElement('span');
             icon.textContent = '📁';
             item.appendChild(icon);
@@ -1586,27 +1615,24 @@ class FileManagerModule {
             item.dataset.path = fullPath;
             item.dataset.type = 'file';
             item.dataset.selected = (isSelected || isMulti) ? 'true' : 'false';
-            const bgColor = (isSelected || isMulti) ? 'var(--bg-tertiary)' : 'transparent';
-            item.style.cssText = 'display:flex;align-items:center;padding:6px 10px;cursor:pointer;border-bottom:1px solid var(--border-color);gap:6px;background:' + bgColor + ';';
-            if (isSelected || isMulti) {
-                item.style.borderLeft = '3px solid var(--accent-color)';
-            }
+            const bgColor = isMulti ? 'var(--bg-tertiary)' : 'transparent';
+            item.style.cssText = 'display:flex;align-items:center;padding:6px 10px;cursor:pointer;border-bottom:1px solid var(--border-color);gap:6px;background:' + bgColor + ';border-left:3px solid ' + (isSelected ? 'var(--accent-color)' : 'transparent') + ';';
             item.onmouseenter = () => { if (!item.dataset.selected) item.style.background = 'var(--bg-tertiary)'; };
             item.onmouseleave = () => { if (!item.dataset.selected) item.style.background = 'transparent'; };
             item.onclick = (e) => {
-                // v4.5.78: Ctrl+click or checkbox for multi-select
-                if (e.ctrlKey || e.metaKey) {
-                    if (this._multiSelect.has(fullPath)) this._multiSelect.delete(fullPath);
-                    else this._multiSelect.add(fullPath);
-                    this._refreshFileList();
-                    return;
-                }
+                // Ctrl/Cmd or Select-mode → toggle in the batch set (no full re-render)
+                if (e.ctrlKey || e.metaKey || this._selectMode) { e.preventDefault(); this._toggleMulti(fullPath); return; }
+                // Plain click → preview AND make it the single selected item
+                this._multiSelect.clear();
+                this._multiSelect.add(fullPath);
                 this._selectedFile = fullPath;
                 this._highlightSelected();
-                const content = this.terminal.fs.readFile(fullPath);
-                this._renderPreview(fullPath, content);
+                this._renderPreview(fullPath, this.terminal.fs.readFile(fullPath));
+                this._updateSelectionStatus();
             };
 
+            item.appendChild(this._makeCheckbox(fullPath, entry.name));
+
             const icon = document.createElement('span');
             icon.textContent = '📄';
             item.appendChild(icon);
@@ -1624,34 +1650,73 @@ class FileManagerModule {
             sidebar.appendChild(item);
         });
 
-        const totalCount = entries.length;
-        this._updateStatus(totalCount + ' item' + (totalCount !== 1 ? 's' : ''));
+        this._itemCount = filteredDirs.length + filteredFiles.length;
+        sidebar.scrollTop = _scrollTop;
+        this._highlightSelected();
+        this._updateSelectionStatus();
+    }
+
+    _makeCheckbox(path, label) {
+        const cb = document.createElement('input');
+        cb.type = 'checkbox';
+        cb.checked = this._multiSelect.has(path);
+        cb.setAttribute('aria-label', 'Select ' + label);
+        cb.style.cssText = 'width:20px;height:20px;min-width:20px;margin:0 6px 0 0;accent-color:var(--accent-color);cursor:pointer;touch-action:manipulation;';
+        cb.onclick = (e) => e.stopPropagation();
+        cb.onchange = () => this._toggleMulti(path);
+        return cb;
+    }
+
+    _toggleMulti(path) {
+        if (this._multiSelect.has(path)) this._multiSelect.delete(path);
+        else this._multiSelect.add(path);
+        this._highlightSelected();
+        this._updateSelectionStatus();
+    }
+
+    _updateSelectionStatus() {
+        const n = this._multiSelect.size;
+        if (n) { this._updateStatus(n + ' selected'); return; }
+        if (this._selectedFile) { this._updateStatus('Preview: ' + this._selectedFile.split('/').pop()); return; }
+        const total = this._itemCount || 0;
+        this._updateStatus(total + ' item' + (total === 1 ? '' : 's'));
+    }
+
+    _exists(path) {
+        const fs = this.terminal.fs;
+        try {
+            if (fs.readFile(path) !== null) return true;
+            if (typeof fs.readDir === 'function' && fs.readDir(path) !== null) return true;
+            if (typeof fs.stat === 'function' && fs.stat(path)) return true;
+        } catch (_e) {}
+        return false;
     }
 
     _highlightSelected() {
         const sidebar = document.getElementById('filemgr-sidebar');
         if (!sidebar) return;
-        const items = sidebar.querySelectorAll('[data-type="file"]');
+        const items = sidebar.querySelectorAll('[data-path]');
         items.forEach(item => {
-            const selected = item.dataset.path === this._selectedFile || this._multiSelect.has(item.dataset.path);
-            item.dataset.selected = selected ? 'true' : 'false';
-            item.style.background = selected ? 'var(--bg-tertiary)' : 'transparent';
-            item.style.borderLeft = selected ? '3px solid var(--accent-color)' : '3px solid transparent';
+            const path = item.dataset.path;
+            const inBatch = this._multiSelect.has(path);
+            const preview = this._selectedFile === path;
+            item.dataset.selected = (inBatch || preview) ? 'true' : 'false';
+            item.style.background = inBatch ? 'var(--bg-tertiary)' : 'transparent';
+            item.style.borderLeft = '3px solid ' + (preview ? 'var(--accent-color)' : 'transparent');
+            const cb = item.querySelector('input[type="checkbox"]');
+            if (cb) cb.checked = inBatch;
         });
     }
 
     // v4.5.78: Batch operations
     _getSelectedPaths() {
-        const paths = [...this._multiSelect];
-        if (this._selectedFile && !paths.includes(this._selectedFile)) paths.push(this._selectedFile);
-        return paths;
+        return [...this._multiSelect];
     }
 
     _batchCopy() {
         const paths = this._getSelectedPaths();
         if (!paths.length) { this._updateStatus('No files selected'); return; }
         this._clipboard = { mode: 'copy', paths: [...paths] };
-        this._multiSelect.clear();
         this._updateStatus('📋 Copied ' + paths.length + ' item(s)');
     }
 
@@ -1659,82 +1724,104 @@ class FileManagerModule {
         const paths = this._getSelectedPaths();
         if (!paths.length) { this._updateStatus('No files selected'); return; }
         this._clipboard = { mode: 'cut', paths: [...paths] };
-        this._multiSelect.clear();
         this._updateStatus('✂️ Cut ' + paths.length + ' item(s)');
     }
 
     _batchPaste() {
-        if (!this._clipboard.paths.length) { this._updateStatus('Clipboard empty'); return; }
-        const dest = '/' + this.currentPath.join('/');
-        let count = 0;
+        if (!this._clipboard || !this._clipboard.paths.length) { this._updateStatus('Clipboard empty'); return; }
+        const fs = this.terminal.fs;
+        const dest = this.currentPath.length ? '/' + this.currentPath.join('/') : '/';
+        let count = 0, skipped = 0;
+        const failed = [];
         this._clipboard.paths.forEach(src => {
             const name = src.split('/').pop();
             const destPath = dest === '/' ? '/' + name : dest + '/' + name;
+            if (destPath === src || destPath.startsWith(src + '/')) { skipped++; return; }
+            if (this._exists(destPath) && !confirm('Overwrite ' + destPath + '?')) { skipped++; return; }
             try {
-                if (this._clipboard.mode === 'copy') {
-                    const content = this.terminal.fs.readFile(src);
-                    if (content !== null) { this.terminal.fs.writeFile(destPath, content); count++; }
-                } else if (this._clipboard.mode === 'cut') {
-                    const content = this.terminal.fs.readFile(src);
-                    if (content !== null) {
-                        this.terminal.fs.writeFile(destPath, content);
-                        this.terminal.fs.deleteFile(src);
-                        count++;
-                    }
-                }
-            } catch (e) { /* skip errors */ }
+                const ok = this._clipboard.mode === 'copy' ? fs.copy(src, destPath) : fs.move(src, destPath);
+                if (ok) count++; else failed.push(src);
+            } catch (_e) { failed.push(src); }
         });
-        if (this._clipboard.mode === 'cut') this._clipboard = { mode: null, paths: [] };
+        if (this._clipboard.mode === 'cut') {
+            this._clipboard = failed.length ? { mode: 'cut', paths: failed } : { mode: null, paths: [] };
+        }
         this._multiSelect.clear();
+        this._selectedFile = null;
         this._refreshFileList();
-        this._updateStatus('📥 Pasted ' + count + ' item(s)');
+        this._updateStatus('📥 Pasted ' + count + ' item(s)' + (skipped ? ' — ' + skipped + ' skipped' : '') + (failed.length ? ' — ' + failed.length + ' failed' : ''));
     }
 
     _batchDelete() {
         const paths = this._getSelectedPaths();
         if (!paths.length) { this._updateStatus('No files selected'); return; }
-        if (!confirm('Delete ' + paths.length + ' file(s)?')) return;
-        let count = 0;
+        if (!confirm('Delete ' + paths.length + ' item(s)?')) return;
+        const fs = this.terminal.fs;
+        let count = 0, failed = 0;
         paths.forEach(p => {
-            try { this.terminal.fs.deleteFile(p); count++; } catch (e) { /* skip */ }
+            try {
+                const ok = typeof fs.rm === 'function' ? fs.rm(p) : fs.deleteFile(p);
+                if (ok) count++; else failed++;
+            } catch (_e) { failed++; }
         });
         this._multiSelect.clear();
         this._selectedFile = null;
         this._refreshFileList();
-        this._updateStatus('🗑️ Deleted ' + count + ' file(s)');
+        this._updateStatus('🗑️ Deleted ' + count + ' item(s)' + (failed ? ' — ' + failed + ' failed' : ''));
     }
 
     _batchRename() {
-        const path = this._selectedFile || (this._multiSelect.size === 1 ? [...this._multiSelect][0] : null);
-        if (!path) { this._updateStatus('Select one file to rename'); return; }
-        const oldName = path.split('/').pop();
-        const newName = prompt('Rename to:', oldName);
-        if (!newName || newName === oldName) return;
-        const dir = path.substring(0, path.lastIndexOf('/')) || '/';
-        const newPath = dir === '/' ? '/' + newName : dir + '/' + newName;
-        try {
-            const content = this.terminal.fs.readFile(path);
-            if (content === null) { this._updateStatus('Cannot read file'); return; }
-            this.terminal.fs.writeFile(newPath, content);
-            this.terminal.fs.deleteFile(path);
+        const paths = this._getSelectedPaths();
+        if (!paths.length) { this._updateStatus('No item selected'); return; }
+        const fs = this.terminal.fs;
+        if (paths.length === 1) {
+            const path = paths[0];
+            const oldName = path.split('/').pop();
+            const newName = (prompt('Rename to:', oldName) || '').trim();
+            if (!newName || newName === oldName) return;
+            if (newName === '.' || newName === '..' || newName.includes('/') || newName.includes('\\')) {
+                this._updateStatus('❌ Invalid file name'); return;
+            }
+            const dir = path.substring(0, path.lastIndexOf('/')) || '/';
+            const newPath = dir === '/' ? '/' + newName : dir + '/' + newName;
+            if (this._exists(newPath)) { this._updateStatus('⚠ Destination already exists'); return; }
+            if (!fs.rename(path, newPath)) { this._updateStatus('❌ Rename failed'); return; }
             this._selectedFile = newPath;
             this._multiSelect.clear();
+            this._multiSelect.add(newPath);
             this._refreshFileList();
             this._updateStatus('📝 Renamed to ' + newName);
-        } catch (e) { this._updateStatus('Rename failed: ' + e.message); }
+            return;
+        }
+        const prefix = (prompt('Rename ' + paths.length + ' items — new prefix:', 'file') || '').trim();
+        if (!prefix) return;
+        let i = 0, ok = 0, skip = 0;
+        paths.forEach(p => {
+            const ext = (p.match(/\.[^./]+$/) || [''])[0];
+            const dir = p.substring(0, p.lastIndexOf('/')) || '/';
+            const dest = (dir === '/' ? '' : dir) + '/' + prefix + (++i) + ext;
+            if (dest === p || this._exists(dest)) { skip++; return; }
+            try { if (fs.rename(p, dest)) ok++; else skip++; } catch (_e) { skip++; }
+        });
+        this._multiSelect.clear();
+        this._selectedFile = null;
+        this._refreshFileList();
+        this._updateStatus('📝 Renamed ' + ok + ' item(s)' + (skip ? ' — ' + skip + ' skipped' : ''));
     }
 
     _toggleSelectAll() {
         const sidebar = document.getElementById('filemgr-sidebar');
         if (!sidebar) return;
-        const fileItems = sidebar.querySelectorAll('[data-type="file"]');
-        if (this._multiSelect.size >= fileItems.length) {
-            this._multiSelect.clear();
+        const paths = [...sidebar.querySelectorAll('[data-path]')].map(i => i.dataset.path);
+        if (!paths.length) { this._updateSelectionStatus(); return; }
+        const all = paths.every(p => this._multiSelect.has(p));
+        if (all) {
+            paths.forEach(p => this._multiSelect.delete(p));
+            if (this._selectedFile && paths.includes(this._selectedFile)) this._selectedFile = null;
         } else {
-            fileItems.forEach(item => this._multiSelect.add(item.dataset.path));
+            paths.forEach(p => this._multiSelect.add(p));
         }
         this._refreshFileList();
-        this._updateStatus(this._multiSelect.size + ' selected');
     }
 
     _renderPreview(path, content) {
@@ -1789,20 +1876,12 @@ class FileManagerModule {
     }
 
     _actionDelete() {
-        if (!this._selectedFile) {
-            this._updateStatus('No file selected to delete');
-            return;
-        }
-        if (!confirm('Delete ' + this._selectedFile + '?')) return;
-        const ok = this.terminal.fs.deleteFile(this._selectedFile);
-        if (ok) {
-            this._selectedFile = null;
-            this._refreshFileList();
-            this._clearPreview();
-            this._updateStatus('✅ Deleted');
-        } else {
-            this._updateStatus('❌ Failed to delete');
+        // Delegate to the batch path so checkbox selections are honoured, not just the previewed file.
+        if (!this._getSelectedPaths().length && this._selectedFile) {
+            this._multiSelect.add(this._selectedFile);
         }
+        this._batchDelete();
+        this._clearPreview();
     }
 
     _actionDownload() {
diff --git a/modules/ext/filemgr.js b/modules/ext/filemgr.js
index acbb963..28c62ce 100644
--- a/modules/ext/filemgr.js
+++ b/modules/ext/filemgr.js
@@ -9,6 +9,8 @@ class FileManagerModule {
         this._overlay = null;
         this._selectedFile = null;
         this._multiSelect = new Set();  // v4.5.78: multi-select for batch ops
+        this._selectMode = false;       // v4.6.35: tap-to-select mode (touch devices)
+        this._itemCount = 0;            // items rendered in the current directory/filter
         this._clipboard = { mode: null, paths: [] };  // 'copy' or 'cut'
         this._searchFilter = '';
         this._rawMode = false;
@@ -426,6 +428,15 @@ class FileManagerModule {
         batchBar.appendChild(mkBtn('🗑️ Del', 'Delete selected files', () => this._batchDelete()));
         batchBar.appendChild(mkBtn('📝 Rename', 'Rename selected file', () => this._batchRename()));
         batchBar.appendChild(mkBtn('☐ All', 'Toggle select all', () => this._toggleSelectAll()));
+        // v4.6.35: tap-to-select mode — the only usable multi-select path on touch devices
+        const selModeBtn = mkBtn('☑ Select', 'Toggle tap-to-select mode (touch)', () => {
+            this._selectMode = !this._selectMode;
+            selModeBtn.style.background = this._selectMode ? 'var(--accent-color)' : 'none';
+            selModeBtn.style.color = this._selectMode ? '#fff' : 'var(--text-color)';
+            this._updateStatus(this._selectMode ? 'Select mode ON — tap rows to select' : 'Select mode OFF');
+        });
+        selModeBtn.setAttribute('aria-pressed', 'false');
+        batchBar.appendChild(selModeBtn);
         toolbar.appendChild(batchBar);
 
         overlay.appendChild(toolbar);
@@ -527,6 +538,9 @@ class FileManagerModule {
         if (this._overlay) {
             this._overlay.style.display = 'none';
         }
+        this._multiSelect.clear();
+        this._selectedFile = null;
+        this._selectMode = false;
     }
 
     _clearOverlay() {
@@ -535,6 +549,8 @@ class FileManagerModule {
         }
         this._overlay = null;
         this._selectedFile = null;
+        this._multiSelect.clear();
+        this._selectMode = false;
         this._searchFilter = '';
         this._rawMode = false;
     }
@@ -542,6 +558,7 @@ class FileManagerModule {
     _navigateTo(pathParts) {
         this.currentPath = pathParts || [];
         this._selectedFile = null;
+        this._multiSelect.clear();
         this._searchFilter = '';
         const searchInput = this._overlay?.querySelector('input[type="text"]');
         if (searchInput) searchInput.value = '';
@@ -594,6 +611,13 @@ class FileManagerModule {
         const dirs = entries.filter(e => e.type === 'dir');
         const files = entries.filter(e => e.type !== 'dir');
 
+        // Prune selections that no longer exist here (deleted/moved elsewhere)
+        try {
+            const _live = new Set();
+            entries.forEach(e => _live.add(pathStr === '/' ? '/' + e.name : pathStr + '/' + e.name));
+            [...this._multiSelect].forEach(p => { if (!_live.has(p)) this._multiSelect.delete(p); });
+        } catch (_e) {}
+
         // Sort alphabetically
         dirs.sort((a, b) => a.name.localeCompare(b.name));
         files.sort((a, b) => a.name.localeCompare(b.name));
@@ -607,6 +631,7 @@ class FileManagerModule {
             filteredFiles = files.filter(e => e.name.toLowerCase().includes(q));
         }
 
+        const _scrollTop = sidebar.scrollTop;
         sidebar.innerHTML = '';
 
         if (filteredDirs.length === 0 && filteredFiles.length === 0) {
@@ -614,7 +639,8 @@ class FileManagerModule {
             emptyMsg.style.cssText = 'padding:20px;text-align:center;color:var(--text-muted);';
             emptyMsg.textContent = this._searchFilter ? 'No matching files' : '(empty)';
             sidebar.appendChild(emptyMsg);
-            this._updateStatus('0 files');
+            this._itemCount = 0;
+            this._updateSelectionStatus();
             return;
         }
 
@@ -624,14 +650,17 @@ class FileManagerModule {
             const fullPath = pathStr === '/' ? '/' + entry.name : pathStr + '/' + entry.name;
             item.dataset.path = fullPath;
             item.dataset.type = 'dir';
-            item.style.cssText = 'display:flex;align-items:center;padding:6px 10px;cursor:pointer;border-bottom:1px solid var(--border-color);gap:6px;';
+            item.style.cssText = 'display:flex;align-items:center;padding:6px 10px;cursor:pointer;border-bottom:1px solid var(--border-color);gap:6px;border-left:3px solid transparent;';
             item.onmouseenter = () => { if (!item.dataset.selected) item.style.background = 'var(--bg-tertiary)'; };
             item.onmouseleave = () => { if (!item.dataset.selected) item.style.background = 'transparent'; };
-            item.onclick = () => {
+            item.onclick = (e) => {
+                if (e.ctrlKey || e.metaKey || this._selectMode) { e.preventDefault(); this._toggleMulti(fullPath); return; }
                 const newPath = [...this.currentPath, entry.name];
                 this._navigateTo(newPath);
             };
 
+            item.appendChild(this._makeCheckbox(fullPath, entry.name + '/'));
+
             const icon = document.createElement('span');
             icon.textContent = '📁';
             item.appendChild(icon);
@@ -653,27 +682,24 @@ class FileManagerModule {
             item.dataset.path = fullPath;
             item.dataset.type = 'file';
             item.dataset.selected = (isSelected || isMulti) ? 'true' : 'false';
-            const bgColor = (isSelected || isMulti) ? 'var(--bg-tertiary)' : 'transparent';
-            item.style.cssText = 'display:flex;align-items:center;padding:6px 10px;cursor:pointer;border-bottom:1px solid var(--border-color);gap:6px;background:' + bgColor + ';';
-            if (isSelected || isMulti) {
-                item.style.borderLeft = '3px solid var(--accent-color)';
-            }
+            const bgColor = isMulti ? 'var(--bg-tertiary)' : 'transparent';
+            item.style.cssText = 'display:flex;align-items:center;padding:6px 10px;cursor:pointer;border-bottom:1px solid var(--border-color);gap:6px;background:' + bgColor + ';border-left:3px solid ' + (isSelected ? 'var(--accent-color)' : 'transparent') + ';';
             item.onmouseenter = () => { if (!item.dataset.selected) item.style.background = 'var(--bg-tertiary)'; };
             item.onmouseleave = () => { if (!item.dataset.selected) item.style.background = 'transparent'; };
             item.onclick = (e) => {
-                // v4.5.78: Ctrl+click or checkbox for multi-select
-                if (e.ctrlKey || e.metaKey) {
-                    if (this._multiSelect.has(fullPath)) this._multiSelect.delete(fullPath);
-                    else this._multiSelect.add(fullPath);
-                    this._refreshFileList();
-                    return;
-                }
+                // Ctrl/Cmd or Select-mode → toggle in the batch set (no full re-render)
+                if (e.ctrlKey || e.metaKey || this._selectMode) { e.preventDefault(); this._toggleMulti(fullPath); return; }
+                // Plain click → preview AND make it the single selected item
+                this._multiSelect.clear();
+                this._multiSelect.add(fullPath);
                 this._selectedFile = fullPath;
                 this._highlightSelected();
-                const content = this.terminal.fs.readFile(fullPath);
-                this._renderPreview(fullPath, content);
+                this._renderPreview(fullPath, this.terminal.fs.readFile(fullPath));
+                this._updateSelectionStatus();
             };
 
+            item.appendChild(this._makeCheckbox(fullPath, entry.name));
+
             const icon = document.createElement('span');
             icon.textContent = '📄';
             item.appendChild(icon);
@@ -691,34 +717,73 @@ class FileManagerModule {
             sidebar.appendChild(item);
         });
 
-        const totalCount = entries.length;
-        this._updateStatus(totalCount + ' item' + (totalCount !== 1 ? 's' : ''));
+        this._itemCount = filteredDirs.length + filteredFiles.length;
+        sidebar.scrollTop = _scrollTop;
+        this._highlightSelected();
+        this._updateSelectionStatus();
+    }
+
+    _makeCheckbox(path, label) {
+        const cb = document.createElement('input');
+        cb.type = 'checkbox';
+        cb.checked = this._multiSelect.has(path);
+        cb.setAttribute('aria-label', 'Select ' + label);
+        cb.style.cssText = 'width:20px;height:20px;min-width:20px;margin:0 6px 0 0;accent-color:var(--accent-color);cursor:pointer;touch-action:manipulation;';
+        cb.onclick = (e) => e.stopPropagation();
+        cb.onchange = () => this._toggleMulti(path);
+        return cb;
+    }
+
+    _toggleMulti(path) {
+        if (this._multiSelect.has(path)) this._multiSelect.delete(path);
+        else this._multiSelect.add(path);
+        this._highlightSelected();
+        this._updateSelectionStatus();
+    }
+
+    _updateSelectionStatus() {
+        const n = this._multiSelect.size;
+        if (n) { this._updateStatus(n + ' selected'); return; }
+        if (this._selectedFile) { this._updateStatus('Preview: ' + this._selectedFile.split('/').pop()); return; }
+        const total = this._itemCount || 0;
+        this._updateStatus(total + ' item' + (total === 1 ? '' : 's'));
+    }
+
+    _exists(path) {
+        const fs = this.terminal.fs;
+        try {
+            if (fs.readFile(path) !== null) return true;
+            if (typeof fs.readDir === 'function' && fs.readDir(path) !== null) return true;
+            if (typeof fs.stat === 'function' && fs.stat(path)) return true;
+        } catch (_e) {}
+        return false;
     }
 
     _highlightSelected() {
         const sidebar = document.getElementById('filemgr-sidebar');
         if (!sidebar) return;
-        const items = sidebar.querySelectorAll('[data-type="file"]');
+        const items = sidebar.querySelectorAll('[data-path]');
         items.forEach(item => {
-            const selected = item.dataset.path === this._selectedFile || this._multiSelect.has(item.dataset.path);
-            item.dataset.selected = selected ? 'true' : 'false';
-            item.style.background = selected ? 'var(--bg-tertiary)' : 'transparent';
-            item.style.borderLeft = selected ? '3px solid var(--accent-color)' : '3px solid transparent';
+            const path = item.dataset.path;
+            const inBatch = this._multiSelect.has(path);
+            const preview = this._selectedFile === path;
+            item.dataset.selected = (inBatch || preview) ? 'true' : 'false';
+            item.style.background = inBatch ? 'var(--bg-tertiary)' : 'transparent';
+            item.style.borderLeft = '3px solid ' + (preview ? 'var(--accent-color)' : 'transparent');
+            const cb = item.querySelector('input[type="checkbox"]');
+            if (cb) cb.checked = inBatch;
         });
     }
 
     // v4.5.78: Batch operations
     _getSelectedPaths() {
-        const paths = [...this._multiSelect];
-        if (this._selectedFile && !paths.includes(this._selectedFile)) paths.push(this._selectedFile);
-        return paths;
+        return [...this._multiSelect];
     }
 
     _batchCopy() {
         const paths = this._getSelectedPaths();
         if (!paths.length) { this._updateStatus('No files selected'); return; }
         this._clipboard = { mode: 'copy', paths: [...paths] };
-        this._multiSelect.clear();
         this._updateStatus('📋 Copied ' + paths.length + ' item(s)');
     }
 
@@ -726,82 +791,104 @@ class FileManagerModule {
         const paths = this._getSelectedPaths();
         if (!paths.length) { this._updateStatus('No files selected'); return; }
         this._clipboard = { mode: 'cut', paths: [...paths] };
-        this._multiSelect.clear();
         this._updateStatus('✂️ Cut ' + paths.length + ' item(s)');
     }
 
     _batchPaste() {
-        if (!this._clipboard.paths.length) { this._updateStatus('Clipboard empty'); return; }
-        const dest = '/' + this.currentPath.join('/');
-        let count = 0;
+        if (!this._clipboard || !this._clipboard.paths.length) { this._updateStatus('Clipboard empty'); return; }
+        const fs = this.terminal.fs;
+        const dest = this.currentPath.length ? '/' + this.currentPath.join('/') : '/';
+        let count = 0, skipped = 0;
+        const failed = [];
         this._clipboard.paths.forEach(src => {
             const name = src.split('/').pop();
             const destPath = dest === '/' ? '/' + name : dest + '/' + name;
+            if (destPath === src || destPath.startsWith(src + '/')) { skipped++; return; }
+            if (this._exists(destPath) && !confirm('Overwrite ' + destPath + '?')) { skipped++; return; }
             try {
-                if (this._clipboard.mode === 'copy') {
-                    const content = this.terminal.fs.readFile(src);
-                    if (content !== null) { this.terminal.fs.writeFile(destPath, content); count++; }
-                } else if (this._clipboard.mode === 'cut') {
-                    const content = this.terminal.fs.readFile(src);
-                    if (content !== null) {
-                        this.terminal.fs.writeFile(destPath, content);
-                        this.terminal.fs.deleteFile(src);
-                        count++;
-                    }
-                }
-            } catch (e) { /* skip errors */ }
+                const ok = this._clipboard.mode === 'copy' ? fs.copy(src, destPath) : fs.move(src, destPath);
+                if (ok) count++; else failed.push(src);
+            } catch (_e) { failed.push(src); }
         });
-        if (this._clipboard.mode === 'cut') this._clipboard = { mode: null, paths: [] };
+        if (this._clipboard.mode === 'cut') {
+            this._clipboard = failed.length ? { mode: 'cut', paths: failed } : { mode: null, paths: [] };
+        }
         this._multiSelect.clear();
+        this._selectedFile = null;
         this._refreshFileList();
-        this._updateStatus('📥 Pasted ' + count + ' item(s)');
+        this._updateStatus('📥 Pasted ' + count + ' item(s)' + (skipped ? ' — ' + skipped + ' skipped' : '') + (failed.length ? ' — ' + failed.length + ' failed' : ''));
     }
 
     _batchDelete() {
         const paths = this._getSelectedPaths();
         if (!paths.length) { this._updateStatus('No files selected'); return; }
-        if (!confirm('Delete ' + paths.length + ' file(s)?')) return;
-        let count = 0;
+        if (!confirm('Delete ' + paths.length + ' item(s)?')) return;
+        const fs = this.terminal.fs;
+        let count = 0, failed = 0;
         paths.forEach(p => {
-            try { this.terminal.fs.deleteFile(p); count++; } catch (e) { /* skip */ }
+            try {
+                const ok = typeof fs.rm === 'function' ? fs.rm(p) : fs.deleteFile(p);
+                if (ok) count++; else failed++;
+            } catch (_e) { failed++; }
         });
         this._multiSelect.clear();
         this._selectedFile = null;
         this._refreshFileList();
-        this._updateStatus('🗑️ Deleted ' + count + ' file(s)');
+        this._updateStatus('🗑️ Deleted ' + count + ' item(s)' + (failed ? ' — ' + failed + ' failed' : ''));
     }
 
     _batchRename() {
-        const path = this._selectedFile || (this._multiSelect.size === 1 ? [...this._multiSelect][0] : null);
-        if (!path) { this._updateStatus('Select one file to rename'); return; }
-        const oldName = path.split('/').pop();
-        const newName = prompt('Rename to:', oldName);
-        if (!newName || newName === oldName) return;
-        const dir = path.substring(0, path.lastIndexOf('/')) || '/';
-        const newPath = dir === '/' ? '/' + newName : dir + '/' + newName;
-        try {
-            const content = this.terminal.fs.readFile(path);
-            if (content === null) { this._updateStatus('Cannot read file'); return; }
-            this.terminal.fs.writeFile(newPath, content);
-            this.terminal.fs.deleteFile(path);
+        const paths = this._getSelectedPaths();
+        if (!paths.length) { this._updateStatus('No item selected'); return; }
+        const fs = this.terminal.fs;
+        if (paths.length === 1) {
+            const path = paths[0];
+            const oldName = path.split('/').pop();
+            const newName = (prompt('Rename to:', oldName) || '').trim();
+            if (!newName || newName === oldName) return;
+            if (newName === '.' || newName === '..' || newName.includes('/') || newName.includes('\\')) {
+                this._updateStatus('❌ Invalid file name'); return;
+            }
+            const dir = path.substring(0, path.lastIndexOf('/')) || '/';
+            const newPath = dir === '/' ? '/' + newName : dir + '/' + newName;
+            if (this._exists(newPath)) { this._updateStatus('⚠ Destination already exists'); return; }
+            if (!fs.rename(path, newPath)) { this._updateStatus('❌ Rename failed'); return; }
             this._selectedFile = newPath;
             this._multiSelect.clear();
+            this._multiSelect.add(newPath);
             this._refreshFileList();
             this._updateStatus('📝 Renamed to ' + newName);
-        } catch (e) { this._updateStatus('Rename failed: ' + e.message); }
+            return;
+        }
+        const prefix = (prompt('Rename ' + paths.length + ' items — new prefix:', 'file') || '').trim();
+        if (!prefix) return;
+        let i = 0, ok = 0, skip = 0;
+        paths.forEach(p => {
+            const ext = (p.match(/\.[^./]+$/) || [''])[0];
+            const dir = p.substring(0, p.lastIndexOf('/')) || '/';
+            const dest = (dir === '/' ? '' : dir) + '/' + prefix + (++i) + ext;
+            if (dest === p || this._exists(dest)) { skip++; return; }
+            try { if (fs.rename(p, dest)) ok++; else skip++; } catch (_e) { skip++; }
+        });
+        this._multiSelect.clear();
+        this._selectedFile = null;
+        this._refreshFileList();
+        this._updateStatus('📝 Renamed ' + ok + ' item(s)' + (skip ? ' — ' + skip + ' skipped' : ''));
     }
 
     _toggleSelectAll() {
         const sidebar = document.getElementById('filemgr-sidebar');
         if (!sidebar) return;
-        const fileItems = sidebar.querySelectorAll('[data-type="file"]');
-        if (this._multiSelect.size >= fileItems.length) {
-            this._multiSelect.clear();
+        const paths = [...sidebar.querySelectorAll('[data-path]')].map(i => i.dataset.path);
+        if (!paths.length) { this._updateSelectionStatus(); return; }
+        const all = paths.every(p => this._multiSelect.has(p));
+        if (all) {
+            paths.forEach(p => this._multiSelect.delete(p));
+            if (this._selectedFile && paths.includes(this._selectedFile)) this._selectedFile = null;
         } else {
-            fileItems.forEach(item => this._multiSelect.add(item.dataset.path));
+            paths.forEach(p => this._multiSelect.add(p));
         }
         this._refreshFileList();
-        this._updateStatus(this._multiSelect.size + ' selected');
     }
 
     _renderPreview(path, content) {
@@ -856,20 +943,12 @@ class FileManagerModule {
     }
 
     _actionDelete() {
-        if (!this._selectedFile) {
-            this._updateStatus('No file selected to delete');
-            return;
-        }
-        if (!confirm('Delete ' + this._selectedFile + '?')) return;
-        const ok = this.terminal.fs.deleteFile(this._selectedFile);
-        if (ok) {
-            this._selectedFile = null;
-            this._refreshFileList();
-            this._clearPreview();
-            this._updateStatus('✅ Deleted');
-        } else {
-            this._updateStatus('❌ Failed to delete');
+        // Delegate to the batch path so checkbox selections are honoured, not just the previewed file.
+        if (!this._getSelectedPaths().length && this._selectedFile) {
+            this._multiSelect.add(this._selectedFile);
         }
+        this._batchDelete();
+        this._clearPreview();
     }
 
     _actionDownload() {