refactor(frontend): remove FSD shim files and dead code
- Break entity shim chain: brokerPositionApi, brokerOperationApi now use shared/api/client directly
- Remove all 43 shim re-export files (api/, hooks/, context/, components/, pages/ flat shims, routes.tsx)
- Remove entire pages/broker/ dead code directory
- Remove api/broker.ts after breaking the shim chain
- Switch auth consumers from AuthProvider (shim) to SessionProvider (FSD)
- Fix api/screener.ts imports to use @/shared/api
- Update frontend hooks.md and routes.md documentation
- 2840 lines removed, 71 lines added
Sergey Krylov
b069575fbb