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>

tests/unit/test_earnings_research.py

@@ -1,6 +1,5 @@
 from datetime import date, timedelta
 
-from scripts.backfill_earnings_events import _dedupe_bulk_rows, _windows
 from scripts.import_dolthub_earnings import _align_symbol
 from scripts.run_earnings_research import (
     _analyse_2a_trades,
@@ -41,42 +40,6 @@ def test_dolthub_alignment_allows_fiscal_period_label_after_announcement() -> No
     assert matches == [(0, 0), (1, 1)]
 
 
-def test_bulk_windows_cover_range_without_overlap() -> None:
-    result = _windows(date(2020, 1, 1), date(2020, 1, 10), 4)
-    assert result == [
-        (date(2020, 1, 1), date(2020, 1, 4)),
-        (date(2020, 1, 5), date(2020, 1, 8)),
-        (date(2020, 1, 9), date(2020, 1, 10)),
-    ]
-
-
-def test_bulk_dedupe_prefers_more_complete_and_counts_restatement() -> None:
-    rows = [
-        {
-            "symbol": "AAPL",
-            "announce_date": "2024-01-01",
-            "announce_time": None,
-            "eps_estimate": 1.0,
-            "eps_actual": 1.1,
-            "revenue_estimate": None,
-            "revenue_actual": None,
-        },
-        {
-            "symbol": "AAPL",
-            "announce_date": "2024-01-01",
-            "announce_time": "amc",
-            "eps_estimate": 1.0,
-            "eps_actual": 1.2,
-            "revenue_estimate": 10.0,
-            "revenue_actual": 11.0,
-        },
-    ]
-    deduped, duplicates, restated = _dedupe_bulk_rows(rows)
-    assert duplicates == 1
-    assert restated == 1
-    assert deduped == [rows[1]]
-
-
 def test_2a_uses_net_r_strict_hold_and_next_session_stop() -> None:
     calendar = [
         date(2024, 1, 2),