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>

app/services/fundamentals_quality_service.py

@@ -12,7 +12,6 @@ from app.models.data_import_run import DataImportRun
 from app.models.fundamental_snapshot import FundamentalSnapshot
 from app.models.sec_filing_gap import SecFilingGap
 from app.models.ticker import Ticker
-from app.services import fundamental_data_refresh_service
 
 _SEC_FORMS = ("10-K", "10-Q", "10-K/A", "10-Q/A")
 
@@ -78,8 +77,6 @@ async def blocked_reasons_by_cik(
     ciks: set[str] | None = None,
 ) -> dict[str, str]:
     """Current SEC blocker code by CIK; no historical audit scan."""
-    if not await fundamental_data_refresh_service.is_enabled(db):
-        return {}
     if ciks is not None and not ciks:
         return {}