feat(studio): unify resource detail layouts

[evanlowe]

Summary

• add a reusable resource detail shell with shared header, navigation, and split-body layout
• apply the shell to knowledge bases, skills, environments, agents, workspaces, and scheduled tasks
• standardize resource tables and action menus while using native Apps SDK UI buttons
• simplify resource metadata and package the rebuilt Studio assets

Validation

• pre-commit run --all-files
• npm test (946 tests)
• npx tsc --noEmit
• npm run build
• npm run test:webui-assets
• desktop and 390x844 responsive visual review