feat(console-web): complete Create member flows for Workflow Script and GAgent

[potter-sun]

Background

The Create member modal already exposes Workflow, Script, and GAgent as implementation kinds, and the frontend has a real createMember API. The remaining gap is that Script and GAgent still read as transitional handoffs rather than first-class member creation flows.

Scope

• Route all implementation kinds through the member authority creation API.
• Normalize Create member copy so Workflow, Script, and GAgent are peers.
• After creation, navigate to the correct Build surface for the selected implementation kind.
• Ensure created members appear in the member rail with implementation kind and lifecycle state.
• Keep behavior honest when a specific implementation editor is unavailable.

Acceptance Criteria

• Workflow Create member creates a backend member and opens workflow Build.
• Script Create member creates a backend member and opens script Build with a stable script draft identity.
• GAgent Create member creates a backend member and opens GAgent Build.
• The modal no longer presents Script or GAgent as future-only transitional paths when backend creation succeeds.
• Tests cover all three implementation kinds.

Verification

• npm --prefix apps/aevatar-console-web run tsc
• npm --prefix apps/aevatar-console-web run build
• npm --prefix apps/aevatar-console-web run test -- --runInBand src/pages/studio/index.test.tsx src/pages/studio/components/StudioShell.test.tsx

References

• apps/aevatar-console-web/src/pages/studio/index.tsx
• apps/aevatar-console-web/src/shared/studio/api.ts
• apps/aevatar-console-web/src/shared/studio/models.ts
• src/Aevatar.Studio.Hosting/Endpoints/StudioMemberEndpoints.cs