fix: apply --app-name to web page titles

[MicahZoltu]

An exact copy of the PR in #7725 by @jonathandunne, but rebased against latest. Fixes #7688 Original PR description below:

Summary

• apply --app-name to VS Code web bootstrap product configuration
• set nameShort/nameLong so ${appName} in tab titles uses the configured app name
• add a focused route test covering the injected configuration

Testing

• attempted npm install (partially completed but failed in lib/vscode on missing gssapi/gssapi.h for kerberos under Node 24)
• attempted npm run test:unit -- --runInBand --runTestsByPath test/unit/node/routes/vscode.test.ts test/unit/node/routes/login.test.ts
• test run was blocked by a pre-existing TypeScript error in src/node/http.ts (auth.cookie-max-age missing on DefaultedArgs) before these route tests executed

[MicahZoltu]

In the original PR @code-asher asked:

I feel like it would make a lot of sense to add this to the integration.diff patch instead of a separate one. What do you think?

At a glance it appears that each file has a single block of prose text at the top describing its purpose. If we were to integrate this into integration.diff then we would have to drop the descriptive comment currently in the app-name.diff header, or figure out some other way to to include it. I feel like the human readable description being near the change is valuable.

Is there some other way to add comments to diffs? I'm not familiar with the format. We could add the description of this to the existing integration.diff header, but I feel like that would be confusing. My instinct (knowing very little about this project's structure) is that each cohesive change should be isolated into its own file, similar to how one would have a commit or PR for each change. This way when something breaks due to an upstream change, the diffs associated with it are consolidated together.

Note: I spent more time writing these two paragraphs than I did investigating, so I may be way off base or there may be an obvious solution!