Fix Aspire AppHost not building email templates before APIs become ready

[tjementum]

Summary & Motivation

After the localized-emails feature merged to main, starting Aspire on a fresh clone (or any environment without a populated application/account/WebApp/emails/dist/ folder) returned HTTP 500 from every email-sending endpoint with System.IO.FileNotFoundException: Email template 'StartSignup.en-US.html' not found. The crash cascaded through 11 of 14 e2e smoke tests. The dist folder is a gitignored build artifact only populated by the @repo/emails#build turbo task; nothing in the dev pipeline triggered that task before the AppGateway accepted requests.

• Add @repo/emails#build to dev:setup's dependsOn in application/turbo.json. The Aspire AppHost's frontendBuild resource runs npm start → turbo dev, and dev depends on dev:setup. Hooking @repo/emails#build into dev:setup makes turbo block every package's dev server until the email dist exists. The same flow protects every entry point that funnels through turbo dev — pp restart, pp run, pp e2e, dotnet run --project AppHost, and any IDE-launched AppHost.
• Update the UnknownUser e2e assertions in application/account/WebApp/tests/e2e/localized-email-flows.spec.ts to match the Slack-style copy the email template was rewritten to use ("No account found" / "Is this the right email address?" in English, "Ingen konto fundet" / "Er det den rigtige e-mailadresse?" in Danish). The previous strings ("Unknown user tried to login to PlatformPlatform" / "You or someone else tried to login to PlatformPlatform") no longer exist in the rendered emails.

Checklist

• I have added tests, or done manual regression tests
• I have updated the documentation, if necessary

[linear]

PP-1197 Aspire AppHost does not build email templates before APIs become ready

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud