Refactor: Move DashboardFilterProvider to pages directory

- Move DashboardFilterProvider component and tests from providers/ to pages/
- Update DashboardPage imports to reflect new structure
- Update documentation with latest task progress

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Docs/Tasks.md

@@ -1,27 +1,3 @@
-### T-18 · Merge `useDashboardCountryData` and `useMapData` — near-identical hooks
-
-**Where found:** `frontend/src/hooks/useDashboardCountryData.ts` and `frontend/src/hooks/useMapData.ts`
-
-**Why this is needed:** Both hooks call `fetchBansByCountry`, maintain the same state shape (`countries`, `countryNames`, `bans`, `total`, `loading`, `error`), and implement the same abort-controller pattern. The only behavioural difference is that `useMapData` adds a 300ms debounce. Any bug fix must be applied to both.
-
-**Goal:** A single `useBansByCountry` base hook; `useMapData` adds the debounce on top.
-
-**What to do:**
-1. Create `useBansByCountry(range, origin, source, countryCode?)` — the shared fetch logic without debounce.
-2. Refactor `useDashboardCountryData` to wrap `useBansByCountry`.
-3. Refactor `useMapData` to wrap `useBansByCountry` and add the debounce layer.
-4. Keep the existing hook names as thin wrappers to preserve call sites.
-
-**Possible traps and issues:**
-- `useMapData` returns `{ data }` (the full response object) whereas `useDashboardCountryData` unpacks `countries`, `countryNames`, `bans`, `total`. Normalise the return shape before collapsing.
-- Tests for each hook test them independently — update or merge.
-
-**Docs changes needed:** None.
-
-**Doc references:** `frontend/src/hooks/useDashboardCountryData.ts`, `frontend/src/hooks/useMapData.ts`
-
----
-
 ### T-19 · Move `DashboardFilterProvider` — page-scoped provider in wrong directory
 
 **Where found:** `frontend/src/providers/DashboardFilterProvider.tsx` — instantiated only inside `DashboardPage.tsx`