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>

frontend/src/pages/DashboardPage.tsx

@@ -16,7 +16,7 @@ import { TopCountriesBarChart } from "../components/TopCountriesBarChart";
 import { TopCountriesPieChart } from "../components/TopCountriesPieChart";
 import { useCommonSectionStyles } from "../components/commonStyles";
 import { useDashboardCountryData } from "../hooks/useDashboardCountryData";
-import { DashboardFilterProvider, useDashboardFilters } from "../providers/DashboardFilterProvider";
+import { DashboardFilterProvider, useDashboardFilters } from "./DashboardFilterProvider";
 
 
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