Apply --app-name to VS Code web page titles

VS Code's `${appName}` title variable comes from `productService.nameLong` in the
web client. code-server already injects per-request product configuration into
VS Code's web bootstrap, so set `nameShort`/`nameLong` from the existing
`--app-name` CLI arg there.

This keeps the patch minimal and makes browser tab titles honor `--app-name`
without changing unrelated product metadata.

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
@@ -333,8 +333,11 @@ export class WebClientServer {
 			scopes: [['user:email'], ['repo']]
 		} : undefined;
 
+		const appName = this._environmentService.args['app-name'];
 		const productConfiguration = {
 			embedderIdentifier: 'server-distro',
+			nameShort: appName,
+			nameLong: appName,
 			extensionsGallery: this._webExtensionResourceUrlTemplate && this._productService.extensionsGallery ? {
 				...this._productService.extensionsGallery,
 				resourceUrlTemplate: this._webExtensionResourceUrlTemplate.with({