Add a service worker

To test try installing code-server as a PWA.

Index: code-server/lib/vscode/src/vs/base/common/product.ts
===================================================================
--- code-server.orig/lib/vscode/src/vs/base/common/product.ts
+++ code-server/lib/vscode/src/vs/base/common/product.ts
@@ -36,6 +36,10 @@ export interface IProductConfiguration {
 	readonly updateEndpoint?: string
 	readonly logoutEndpoint?: string
 	readonly proxyEndpointTemplate?: string
+	readonly serviceWorker?: {
+		readonly path: string;
+		readonly scope: string;
+	}
 
 	readonly version: string;
 	readonly date?: string;
Index: code-server/lib/vscode/src/vs/server/node/webClientServer.ts
===================================================================
--- code-server.orig/lib/vscode/src/vs/server/node/webClientServer.ts
+++ code-server/lib/vscode/src/vs/server/node/webClientServer.ts
@@ -315,6 +315,10 @@ export class WebClientServer {
 				updateEndpoint: !this._environmentService.args['disable-update-check'] ? base + '/update/check' : undefined,
 				logoutEndpoint: this._environmentService.args['auth'] ? base + '/logout' : undefined,
 				proxyEndpointTemplate: base + '/proxy/{{port}}',
+				serviceWorker: {
+					scope: vscodeBase + '/',
+					path: base + '/_static/out/browser/serviceWorker.js',
+				},
 				embedderIdentifier: 'server-distro',
 				extensionsGallery: this._productService.extensionsGallery,
 			},
Index: code-server/lib/vscode/src/vs/workbench/browser/client.ts
===================================================================
--- code-server.orig/lib/vscode/src/vs/workbench/browser/client.ts
+++ code-server/lib/vscode/src/vs/workbench/browser/client.ts
@@ -90,6 +90,10 @@ export class CodeServerClient extends Di
 		if (this.productService.logoutEndpoint) {
 			this.addLogoutCommand(this.productService.logoutEndpoint);
 		}
+
+		if (this.productService.serviceWorker) {
+			await this.registerServiceWorker(this.productService.serviceWorker);
+		}
 	}
 
 	private checkUpdates(updateEndpoint: string) {
@@ -162,4 +166,17 @@ export class CodeServerClient extends Di
 			});
 		}
 	}
+
+	private async registerServiceWorker(serviceWorker: { path: string; scope: string }) {
+		if (typeof navigator !== 'undefined' && 'serviceWorker' in navigator) {
+			try {
+				await navigator.serviceWorker.register(serviceWorker.path, {
+					scope: serviceWorker.scope,
+				});
+				this.logService.info('[Service Worker] registered');
+			} catch (error: any) {
+				this.logService.error('[Service Worker] registration', error as Error);
+			}
+		}
+	}
 }