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_activation_settings.py

@@ -8,9 +8,7 @@ from sqlalchemy.ext.asyncio import AsyncSession
 from app.exceptions import ValidationError
 from app.services.admin_service import (
     get_activation_config,
-    get_fundamentals_cutover_config,
     update_activation_config,
-    update_fundamentals_cutover_config,
 )
 
 
@@ -78,18 +76,3 @@ class TestActivationConfig:
     async def test_rejects_out_of_range_confidence(self, session: AsyncSession):
         with pytest.raises(ValidationError):
             await update_activation_config(session, {"min_confidence": 120.0})
-
-
-class TestFundamentalsCutoverConfig:
-    async def test_defaults_off_when_unset(self, session: AsyncSession):
-        assert await get_fundamentals_cutover_config(session) == {"enabled": False}
-
-    async def test_round_trips_explicit_switch(self, session: AsyncSession):
-        assert await update_fundamentals_cutover_config(session, True) == {
-            "enabled": True
-        }
-        assert await get_fundamentals_cutover_config(session) == {"enabled": True}
-
-        assert await update_fundamentals_cutover_config(session, False) == {
-            "enabled": False
-        }