Add architecture enforcement tests and feature deletion tests

[quinCode]

Add architecture enforcement tests and feature deletion tests

Parent

#2

What to build

Add tests that enforce the new architecture rather than only checking individual behaviors. These tests should ensure feature modules remain removable, feature routes and navigation stay unique, frontend features do not import each other directly, and the integrated path remains covered by a small number of smoke tests.

This slice can be developed alongside feature migrations, but should be complete before the final hard switch.

Acceptance criteria

• Import boundary tests prevent frontend feature-to-feature imports.
• Import boundary tests prevent frontend code from importing backend or core internals.
• Feature registry tests verify module id, route, navigation, and required capability uniqueness.
• Capability validity tests ensure feature-required capabilities are known or intentionally optional.
• Deletion tests remove a feature from the registry and verify the shell and remaining features still work.
• End-to-end smoke tests cover loading the app, selecting config, starting a fake run, observing progress, and viewing results.
• Tests are documented as architecture constraints for future implementation agents.

Blocked by

• Scaffold React/Vite/TypeScript shell with generated API client #6