feat(web): advisory/vex onboarding setup wizard

Sprint SPRINT_20260417_001_Platform_setup_advisory_vex_onboarding
(Platform backend landed in commit 9393baf1a).

- Setup wizard feature: components (setup-wizard, step-content,
  step-content.defaults.spec), models, services
  (setup-wizard-api.service, setup-wizard-state.service) + specs.
- Advisory source catalog component + behavior spec.
- Live setup-wizard first-run bootstrap script + playwright auth/state
  output fixtures.

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

src/Web/StellaOps.Web/output/playwright/live-setup-wizard-first-run-bootstrap.json

@@ -0,0 +1,104 @@
+{
+  "generatedAtUtc": "2026-04-19T11:21:17.727Z",
+  "baseUrl": "https://stella-ops.local",
+  "adminUsername": "admin",
+  "adminEmail": "admin@stella-ops.local",
+  "mode": "already-configured",
+  "steps": [
+    {
+      "action": "setup-entry-after-authentication",
+      "ok": true,
+      "resolvedSurface": "authenticated-reconfigure",
+      "initialAnonymousSession": {
+        "status": 401,
+        "ok": false,
+        "sessionId": null,
+        "currentStepId": "",
+        "sessionStatus": "",
+        "completedAtUtc": null,
+        "steps": [],
+        "raw": {
+          "status": 401,
+          "ok": false,
+          "payload": null,
+          "bodyText": ""
+        }
+      },
+      "authenticatedSetupSessionProbe": {
+        "status": 401,
+        "ok": false,
+        "sessionId": null,
+        "currentStepId": "",
+        "sessionStatus": "",
+        "completedAtUtc": null,
+        "steps": [],
+        "raw": {
+          "status": 401,
+          "ok": false,
+          "payload": null,
+          "bodyText": ""
+        }
+      },
+      "initialSnapshot": {
+        "label": "initial",
+        "url": "https://stella-ops.local/setup-wizard/wizard",
+        "title": "Wizard - StellaOps",
+        "heading": "Setup",
+        "alerts": [],
+        "visibleButtons": [
+          "Apply and ContinueWelcome"
+        ]
+      },
+      "snapshot": {
+        "label": "setup-already-complete",
+        "url": "https://stella-ops.local/setup-wizard/wizard",
+        "title": "Wizard - StellaOps",
+        "heading": "Setup",
+        "alerts": [],
+        "visibleButtons": [
+          "Validate Connection",
+          "Apply and ContinueValkey/Redis Cache"
+        ]
+      }
+    }
+  ],
+  "runtime": {
+    "consoleErrors": [],
+    "pageErrors": [],
+    "requestFailures": [],
+    "responseErrors": [
+      {
+        "page": "https://stella-ops.local/setup-wizard/wizard",
+        "method": "POST",
+        "status": 401,
+        "url": "https://stella-ops.local/api/v1/setup/sessions"
+      }
+    ],
+    "setupApiEvents": [
+      {
+        "page": "https://stella-ops.local/setup-wizard/wizard",
+        "method": "POST",
+        "status": 401,
+        "url": "https://stella-ops.local/api/v1/setup/sessions"
+      },
+      {
+        "page": "https://stella-ops.local/setup-wizard/wizard",
+        "method": "POST",
+        "status": 201,
+        "url": "https://stella-ops.local/api/v1/setup/sessions"
+      },
+      {
+        "page": "https://stella-ops.local/setup-wizard/wizard",
+        "method": "POST",
+        "status": 200,
+        "url": "https://stella-ops.local/api/v1/setup/sessions/setup-installation-20260419111949/steps/database/checks/run"
+      }
+    ]
+  },
+  "postSetupAuthentication": {
+    "finalUrl": "https://stella-ops.local/?tenant=default&regions=apac,eu-west,us-east",
+    "title": "Dashboard - StellaOps",
+    "reportPath": "C:\\dev\\New folder\\git.stella-ops.org\\src\\Web\\StellaOps.Web\\output\\playwright\\live-setup-wizard-first-run-bootstrap.auth.json",
+    "statePath": "C:\\dev\\New folder\\git.stella-ops.org\\src\\Web\\StellaOps.Web\\output\\playwright\\live-setup-wizard-first-run-bootstrap.state.json"
+  }
+}