refactor(web-app-zammad): collapse helpdesk alias into single canonical zammad hostname

meta/server.yml: drop the helpdesk.<domain> canonical + zammad.helpdesk.<domain>
alias pair; the role now publishes only zammad.helpdesk.<domain> as its
canonical vhost.

Also removes the alias-domain Playwright spec that asserted the alias-to-canonical
rewrite — no alias remains to assert.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

roles/web-app-zammad/files/playwright/test-alias-domain.js

@@ -1,31 +0,0 @@
-const { test, expect, request } = require("@playwright/test");
-
-exports.register = function (shared) {
-  test("zammad alias domain maps to the canonical vhost (2xx direct OR 301-to-canonical)", async () => {
-    const baseUrl = shared.env.zammadBaseUrl;
-    expect(baseUrl, "ZAMMAD_BASE_URL must be set").toBeTruthy();
-
-    const canonicalHost = baseUrl.replace(/^https?:\/\//, "").replace(/\/$/, "");
-    const aliasHost = canonicalHost.replace(/^helpdesk\./, "zammad.helpdesk.");
-
-    if (aliasHost === canonicalHost) {
-      test.skip(true, "Alias hostname matches the canonical; nothing to assert.");
-    }
-
-    const aliasUrl = baseUrl.replace(/\/\/[^/]+/, `//${aliasHost}`);
-    const api = await request.newContext({ ignoreHTTPSErrors: true, maxRedirects: 0 });
-    const aliasResp = await api.get(aliasUrl, { maxRedirects: 0 }).catch((err) => err);
-
-    const status = aliasResp.status?.();
-    const isDirect2xx = typeof status === "number" && status >= 200 && status < 300;
-    const isRedirectToCanonical = typeof status === "number" && status >= 300 && status < 400
-      && (aliasResp.headers?.()["location"] || "").includes(canonicalHost);
-
-    expect(
-      isDirect2xx || isRedirectToCanonical,
-      `Alias ${aliasUrl} must either serve 2xx directly (true vhost alias) or 30x-redirect to ${canonicalHost}. Got status=${status ?? aliasResp.message} location=${aliasResp.headers?.()["location"] ?? "<none>"}`
-    ).toBe(true);
-
-    await api.dispose();
-  });
-};

roles/web-app-zammad/meta/server.yml

@@ -1,8 +1,6 @@
 ---
 domains:
   canonical:
-    - helpdesk.{{ DOMAIN_PRIMARY }}
-  aliases:
     - zammad.helpdesk.{{ DOMAIN_PRIMARY }}
 csp:
   flags: