Move FLN_LEVELS_LIST + FLNLevelReferenceModal out of RoleDashboards.tsx #138

What this is for

RoleDashboards.tsx is a 3,100+ line file holding all 8 role dashboards. We're moving each piece into its own file so the codebase is easier to navigate.

What to move

FLN_LEVELS_LIST (a data constant) and FLNLevelReferenceModal (a shared popup component that several dashboards use) — together, ~183 lines.

Steps

1. Create frontend/src/components/dashboards/FLNLevelReference.tsx.
2. Cut both FLN_LEVELS_LIST and FLNLevelReferenceModal out of RoleDashboards.tsx into the new file, with whatever imports they need.
3. Back in RoleDashboards.tsx, add: export { FLN_LEVELS_LIST, FLNLevelReferenceModal } from './dashboards/FLNLevelReference'; where they used to be.
4. Don't change any logic — copy it exactly as-is.

Watch out for

• This one is used by other dashboards (search the file for FLNLevelReferenceModal and FLN_LEVELS_LIST to see which ones), so do this one before the dashboard-specific issues if possible — it'll make those easier.

How to check your work

1. cd frontend && npm run lint — no errors.
2. npm run build — succeeds.
3. Run npm run dev, open the "FLN Level Reference" popup from any dashboard that has it, and confirm it still opens and shows the same content as before.

Part of #136.