Fix Aspire AppHost not building email templates before APIs become ready (#886)

### 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

- [x] I have added tests, or done manual regression tests
- [x] I have updated the documentation, if necessary

Author: tjementum

application/account/WebApp/tests/e2e/localized-email-flows.spec.ts

@@ -238,10 +238,10 @@ test.describe("@comprehensive", () => {
     await step("Fetch en-US unknown user email from Mailpit & assert subject, HTML, and plaintext")(async () => {
       const mail = await fetchLatestMailByRecipient(enUnknownEmail);
 
-      expect(mail.subject).toBe("Unknown user tried to login to PlatformPlatform");
-      expect(mail.html).toContain("You or someone else tried to login to PlatformPlatform");
+      expect(mail.subject).toBe("No account found");
+      expect(mail.html).toContain("Is this the right email address?");
       expect(mail.html).toContain(enUnknownEmail);
-      expect(mail.text).toContain("You or someone else tried to login to PlatformPlatform");
+      expect(mail.text).toContain("Is this the right email address?");
       expect(mail.text).toContain(enUnknownEmail);
     })();
 
@@ -261,10 +261,10 @@ test.describe("@comprehensive", () => {
       async () => {
         const mail = await fetchLatestMailByRecipient(daUnknownEmail);
 
-        expect(mail.subject).toBe("Ukendt bruger forsøgte at logge ind på PlatformPlatform");
-        expect(mail.html).toContain("Du eller en anden forsøgte at logge ind på PlatformPlatform");
+        expect(mail.subject).toBe("Ingen konto fundet");
+        expect(mail.html).toContain("Er det den rigtige e-mailadresse?");
         expect(mail.html).toContain(daUnknownEmail);
-        expect(mail.text).toContain("Du eller en anden forsøgte at logge ind på PlatformPlatform");
+        expect(mail.text).toContain("Er det den rigtige e-mailadresse?");
         expect(mail.text).toContain(daUnknownEmail);
       }
     )();

application/turbo.json

@@ -37,7 +37,7 @@
       "dependsOn": ["dev:setup"]
     },
     "dev:setup": {
-      "dependsOn": ["^dev:setup"],
+      "dependsOn": ["^dev:setup", "@repo/emails#build"],
       "inputs": ["$TURBO_DEFAULT$", "shared/lib/api/*.Api.json", "shared/lib/api/*.Api_*.json"],
       "outputs": ["dist/**", "shared/lib/api/*.generated.d.ts"]
     },