Persist scenario switching and import-profile execution

[Felix-Zuo]

Extend the existing scenario profile catalog so users can activate a profile and run its import and decision loop without code changes.

Acceptance criteria:

• persist the selected profile locally;
• apply profile-specific users, source contracts and release controls;
• include runnable import-profile samples for fulfillment, maintenance-kit and quality-lab scenarios;
• add API, snapshot and UI tests for switching and reload behavior;
• keep all public samples synthetic.

[Felix-Zuo]

v0.3.1 adds the first reusable scenario profile layer:

• demo_data/scenario_profiles.json for manufacturing assembly, warehouse fulfillment, maintenance-kit operations and quality-lab review.
• scenario_profiles SQLite seed support and GET /api/scenario-profiles.
• Product Plan UI showing profile domain, required sources, controls and operating roles.
• pytest, smoke and frontend snapshot checks.

Leaving this open because persisted scenario switching/import-profile execution is still v0.4 work.

[Felix-Zuo]

The original scenario-profile catalog shipped in v0.3.1 and remains visible in the dashboard and public showcase. The issue has been retitled and narrowed to the unfinished work: persisted profile selection plus runnable import-profile execution.

v0.3.3 also updates the public wording so profiles are presented as configuration boundaries rather than unsupported claims.