Prove invoice coding and collaboration layout on mocks with a fixture PDF viewer, editable header/lines, Comments/Activity feeds, and role-aware action stubs via mock session switching.
* feat(settings): add settings and approvals POC shells (AP-7)
Add app shell nav plus mock settings CRUD routes and an approvals inbox so the POC demo path works without an API.
* fix(build): generate router types before tsc
CI failed because src/router.ts is gitignored and tsc ran before Vite created it.
