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

[jonathandunne]

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

[code-asher]

Thank you for figuring this out! Sorry it has taken me a while to get to this, I should be able to properly test and review this week but some initial comments:

• Could we remove the Helm, doc, and cookie changes? They seem unrelated to the core fix. (Although maybe some of this is just the result of a conflict and a rebase will solve it.) I do see the comment about the test run being blocked, let me look into that soon.
• 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?
• More of a note to myself, does this affect the patch we make to aboutDetail? Wonder if it will show code-server twice now or something.