chore: decommission FMP, Finnhub and Alpha Vantage (A6)

The A5 cutover has been on and observed in production, so SEC Company Facts +
DoltHub earnings are already the live source for `fundamental_data`. This
removes everything the legacy path still occupied.

Gone: the three providers and their config/env keys; the weekly
`fundamental_collector` job; the cutover toggle (SEC + Dolt is now the
unconditional path, so `off` can no longer silently freeze scoring inputs); the
A5 parity report, whose deltas became structurally zero once the candidate
builder started writing the table it compared against; and the FMP tier of
universe bootstrap.

Two behavioral notes:

- Disabling **SEC Fundamentals Import** now stops the SEC network fetch only.
  The local cache refresh moved outside the job-enable check, because candidates
  also derive from daily closes and earnings events — freezing those on an
  ingestion pause would stale scoring with no fallback left to recover from.
- `/ingestion/fetch?sources=fundamentals` still accepts the key and reports
  `skipped`; there is no per-ticker fetch any more.

Migration 029 does not blanket-delete the leftover settings rows. Migrations run
before the service restart, and pre-A6 code reads an absent `job_*_enabled` row
as *enabled* — so the two behavior-bearing keys become tombstones pinned to safe
values (hidden in Admin) and only the inert three are deleted. Removing the
provider keys from the production `.env` is the matching rollout step.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

frontend/src/hooks/useAdmin.ts

@@ -90,36 +90,6 @@ export function useUpdateSetting() {
   });
 }
 
-export function useFundamentalsCutoverSettings() {
-  return useQuery({
-    queryKey: ['admin', 'fundamentals-cutover'],
-    queryFn: () => adminApi.getFundamentalsCutoverSettings(),
-  });
-}
-
-export function useUpdateFundamentalsCutoverSettings() {
-  const qc = useQueryClient();
-  const { addToast } = useToast();
-
-  return useMutation({
-    mutationFn: (enabled: boolean) =>
-      adminApi.updateFundamentalsCutoverSettings(enabled),
-    onSuccess: (config) => {
-      qc.setQueryData(['admin', 'fundamentals-cutover'], config);
-      qc.invalidateQueries({ queryKey: ['admin', 'settings'] });
-      addToast(
-        config.enabled ? 'success' : 'info',
-        config.enabled
-          ? 'SEC + Dolt fundamentals activated'
-          : 'SEC + Dolt cache refresh paused',
-      );
-    },
-    onError: (error: Error) => {
-      addToast('error', error.message || 'Failed to update fundamentals data source');
-    },
-  });
-}
-
 export function useRecommendationSettings() {
   return useQuery({
     queryKey: ['admin', 'recommendation-settings'],
@@ -346,14 +316,6 @@ export function useJobs() {
   });
 }
 
-export function useFundamentalsParityReport() {
-  return useQuery({
-    queryKey: ['admin', 'fundamentals-parity'],
-    queryFn: () => adminApi.getFundamentalsParityReport(),
-    refetchInterval: 15_000,
-  });
-}
-
 export function usePipelineReadiness() {
   return useQuery({
     queryKey: ['admin', 'pipeline-readiness'],