Fix backup API 404s, hardware status 500, and HTMX loading race

- Add all backup API routes to api_v3.py: preview, list, export,
  validate, restore (with plugin reinstall), download, delete
- Fix PermissionError on /hardware/status: return graceful 200 instead
  of 500 when the status file is owned by a different user; also fix
  root cause by writing the file world-readable (0o644) in display_manager
- Fix HTMX race: dispatch htmx:ready window event from HTMX onload
  callback; loadTabContent now waits for that event instead of
  immediately falling back to direct fetch (eliminating the
  "HTMX not available" console warning on initial load)

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

src/display_manager.py

@@ -190,7 +190,7 @@ class DisplayManager:
                         json.dump(_hw_status, _f)
                         _f.flush()
                         os.fsync(_f.fileno())
-                    os.chmod(_tmp_path, 0o600)
+                    os.chmod(_tmp_path, 0o644)
                     os.replace(_tmp_path, _status_path)
                 except Exception:
                     try:

web_interface/blueprints/api_v3.py

@@ -1601,9 +1601,12 @@ def get_hardware_status():
         return jsonify({"status": "success", "data": hw_data})
     except FileNotFoundError:
         return jsonify({"status": "success", "data": {"ok": None, "error": "Display service not yet started"}})
-    except (json.JSONDecodeError, PermissionError):
-        logger.error("Failed to read hardware status file", exc_info=True)
-        return jsonify({"status": "error", "message": "Unable to read hardware status"}), 500
+    except PermissionError:
+        logger.warning("Permission denied reading hardware status file; display service may be running as a different user")
+        return jsonify({"status": "success", "data": {"ok": None, "error": "Hardware status temporarily unavailable"}})
+    except json.JSONDecodeError:
+        logger.error("Failed to parse hardware status file", exc_info=True)
+        return jsonify({"status": "success", "data": {"ok": None, "error": "Hardware status file corrupted"}})
     except Exception:
         logger.error("Unexpected error reading hardware status", exc_info=True)
         return jsonify({"status": "error", "message": "Unable to read hardware status"}), 500
@@ -7064,4 +7067,178 @@ def clear_old_errors():
             message="Failed to clear old errors",
             details=str(e),
             status_code=500
-        )
+        )
+
+
+# ---------------------------------------------------------------------------
+# Backup / Restore
+# ---------------------------------------------------------------------------
+
+_BACKUP_EXPORT_DIR = PROJECT_ROOT / "config" / "backups" / "exports"
+
+
+def _safe_backup_path(filename: str) -> Path:
+    """Resolve a filename to an absolute path inside the export dir,
+    rejecting any traversal attempts. Returns None if unsafe."""
+    if not filename or '/' in filename or '\\' in filename or filename.startswith('.'):
+        return None
+    path = (_BACKUP_EXPORT_DIR / filename).resolve()
+    try:
+        path.relative_to(_BACKUP_EXPORT_DIR.resolve())
+    except ValueError:
+        return None
+    return path
+
+
+@api_v3.route('/backup/preview', methods=['GET'])
+def backup_preview():
+    """Return a summary of what a new backup would include."""
+    try:
+        from src.backup_manager import preview_backup_contents
+        data = preview_backup_contents(PROJECT_ROOT)
+        return jsonify({'status': 'success', 'data': data})
+    except Exception as e:
+        logger.error("backup_preview failed: %s", e, exc_info=True)
+        return jsonify({'status': 'error', 'message': str(e)}), 500
+
+
+@api_v3.route('/backup/list', methods=['GET'])
+def backup_list():
+    """List backup ZIPs stored in the export directory."""
+    try:
+        _BACKUP_EXPORT_DIR.mkdir(parents=True, exist_ok=True)
+        entries = []
+        for p in sorted(_BACKUP_EXPORT_DIR.iterdir(), key=lambda x: x.stat().st_mtime, reverse=True):
+            if not p.is_file() or p.suffix != '.zip':
+                continue
+            st = p.stat()
+            entries.append({
+                'filename': p.name,
+                'size': st.st_size,
+                'created_at': datetime.fromtimestamp(st.st_mtime).strftime('%Y-%m-%d %H:%M:%S'),
+            })
+        return jsonify({'status': 'success', 'data': entries})
+    except Exception as e:
+        logger.error("backup_list failed: %s", e, exc_info=True)
+        return jsonify({'status': 'error', 'message': str(e)}), 500
+
+
+@api_v3.route('/backup/export', methods=['POST'])
+def backup_export():
+    """Create a new backup ZIP and return its filename."""
+    try:
+        from src.backup_manager import create_backup
+        zip_path = create_backup(PROJECT_ROOT, output_dir=_BACKUP_EXPORT_DIR)
+        return jsonify({'status': 'success', 'filename': zip_path.name})
+    except Exception as e:
+        logger.error("backup_export failed: %s", e, exc_info=True)
+        return jsonify({'status': 'error', 'message': str(e)}), 500
+
+
+@api_v3.route('/backup/validate', methods=['POST'])
+def backup_validate():
+    """Validate an uploaded backup ZIP and return its manifest."""
+    try:
+        from src.backup_manager import validate_backup
+        if 'backup_file' not in request.files:
+            return jsonify({'status': 'error', 'message': 'No backup_file in request'}), 400
+        f = request.files['backup_file']
+        with tempfile.NamedTemporaryFile(suffix='.zip', delete=False) as tmp:
+            tmp_path = tmp.name
+            f.save(tmp_path)
+        try:
+            ok, err_msg, manifest = validate_backup(Path(tmp_path))
+        finally:
+            try:
+                os.unlink(tmp_path)
+            except OSError:
+                pass
+        if not ok:
+            return jsonify({'status': 'error', 'message': err_msg}), 400
+        return jsonify({'status': 'success', 'data': manifest})
+    except Exception as e:
+        logger.error("backup_validate failed: %s", e, exc_info=True)
+        return jsonify({'status': 'error', 'message': str(e)}), 500
+
+
+@api_v3.route('/backup/restore', methods=['POST'])
+def backup_restore():
+    """Restore a backup ZIP with optional RestoreOptions."""
+    try:
+        from src.backup_manager import restore_backup, RestoreOptions
+        if 'backup_file' not in request.files:
+            return jsonify({'status': 'error', 'message': 'No backup_file in request'}), 400
+        f = request.files['backup_file']
+        options_raw = request.form.get('options', '{}')
+        try:
+            opts_dict = json.loads(options_raw)
+        except json.JSONDecodeError:
+            opts_dict = {}
+        options = RestoreOptions(
+            restore_config=bool(opts_dict.get('restore_config', True)),
+            restore_secrets=bool(opts_dict.get('restore_secrets', True)),
+            restore_wifi=bool(opts_dict.get('restore_wifi', True)),
+            restore_fonts=bool(opts_dict.get('restore_fonts', True)),
+            restore_plugin_uploads=bool(opts_dict.get('restore_plugin_uploads', True)),
+            reinstall_plugins=bool(opts_dict.get('reinstall_plugins', True)),
+        )
+        with tempfile.NamedTemporaryFile(suffix='.zip', delete=False) as tmp:
+            tmp_path = tmp.name
+            f.save(tmp_path)
+        try:
+            result = restore_backup(Path(tmp_path), PROJECT_ROOT, options)
+        finally:
+            try:
+                os.unlink(tmp_path)
+            except OSError:
+                pass
+
+        # Reinstall plugins if requested and store manager available
+        if options.reinstall_plugins and result.plugins_to_install:
+            psm = getattr(api_v3, 'plugin_store_manager', None) or plugin_store_manager
+            for plug in result.plugins_to_install:
+                pid = plug.get('plugin_id')
+                if not pid:
+                    continue
+                try:
+                    if psm and hasattr(psm, 'install_plugin'):
+                        ok = psm.install_plugin(pid)
+                        if ok:
+                            result.plugins_installed.append(pid)
+                        else:
+                            result.plugins_failed.append({'plugin_id': pid, 'error': 'install_plugin returned False'})
+                    else:
+                        result.plugins_failed.append({'plugin_id': pid, 'error': 'Store manager unavailable'})
+                except Exception as pe:
+                    result.plugins_failed.append({'plugin_id': pid, 'error': str(pe)})
+
+        data = result.to_dict()
+        if not result.success:
+            return jsonify({'status': 'error', 'message': 'Restore had errors', 'data': data}), 500
+        return jsonify({'status': 'success', 'data': data})
+    except Exception as e:
+        logger.error("backup_restore failed: %s", e, exc_info=True)
+        return jsonify({'status': 'error', 'message': str(e)}), 500
+
+
+@api_v3.route('/backup/download/<path:filename>', methods=['GET'])
+def backup_download(filename):
+    """Stream a backup ZIP to the browser."""
+    from flask import send_file
+    path = _safe_backup_path(filename)
+    if path is None or not path.exists():
+        return jsonify({'status': 'error', 'message': 'Backup not found'}), 404
+    return send_file(path, as_attachment=True, download_name=path.name)
+
+
+@api_v3.route('/backup/<path:filename>', methods=['DELETE'])
+def backup_delete(filename):
+    """Delete a stored backup ZIP."""
+    path = _safe_backup_path(filename)
+    if path is None or not path.exists():
+        return jsonify({'status': 'error', 'message': 'Backup not found'}), 404
+    try:
+        path.unlink()
+        return jsonify({'status': 'success'})
+    except OSError as e:
+        return jsonify({'status': 'error', 'message': str(e)}), 500

web_interface/templates/v3/base.html

@@ -152,6 +152,7 @@
                         }
                     } else {
                         console.log('HTMX loaded successfully');
+                        window.dispatchEvent(new Event('htmx:ready'));
                         // Load extensions after core loads
                         loadScript(sseSrc, isAPMode ? 'https://unpkg.com/htmx.org/dist/ext/sse.js' : '/static/v3/js/htmx-sse.js');
                         loadScript(jsonEncSrc, isAPMode ? 'https://unpkg.com/htmx.org/dist/ext/json-enc.js' : '/static/v3/js/htmx-json-enc.js');
@@ -1836,13 +1837,11 @@
                             htmx.trigger(contentEl, 'revealed');
                         }
                     } else {
-                        // HTMX not available, use direct fetch
-                        console.warn('HTMX not available, using direct fetch for tab:', tab);
-                        if (tab === 'overview' && typeof loadOverviewDirect === 'function') {
-                            loadOverviewDirect();
-                        } else if (tab === 'wifi' && typeof loadWifiDirect === 'function') {
-                            loadWifiDirect();
-                        }
+                        // HTMX is still loading asynchronously — retry once it signals ready
+                        const self = this;
+                        window.addEventListener('htmx:ready', function retry() {
+                            self.loadTabContent(tab);
+                        }, { once: true });
                     }
                 },