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>

docs/dolt-integration-plan.md

@@ -430,7 +430,11 @@ workstream B — Alpaca remains the price source throughout.
   approval** — see the handoff section below. Step (c) is implemented behind the
   default-off `fundamental_data_sec_dolt_cutover_enabled` SystemSetting; the
   remaining production action is flipping that switch on and observing it.
-- A6. Remove FMP/Finnhub/Alpha Vantage; keep monitoring + manual fallback.
+- A6. **DONE 2026-08-07.** FMP/Finnhub/Alpha Vantage removed, along with the
+  weekly `fundamental_collector` job, the A5 cutover toggle (SEC+Dolt is now the
+  unconditional path) and the parity report. Migration `029` tombstones the two
+  behavior-bearing settings rows for the rollback window; the archived parity
+  bundles stay as the A5 evidence trail.
 
 **Workstream B (independent, start when wanted):**
 
@@ -507,11 +511,13 @@ managed by the **Fundamentals data source** card in Admin → Settings; while ac
 the weekly legacy collector skips itself so it cannot overwrite the SEC/Dolt cache.
 See `docs/fundamentals-deployment.md` for the production flip and rollback procedure.
 
-**Task 2 — A6 decommissioning.** After a short observation window: remove
-FMP/Finnhub/Alpha Vantage providers, config and env keys; keep monitoring + manual
-fallback. Gated by the acceptance criteria above — especially forward-calendar
-timeliness from `dolt_earnings` (its `source_max_date` ran ~5 weeks ahead as of
-2026-07-23, which passes).
+**Task 2 — A6 decommissioning: DONE 2026-08-07.** The cutover ran on and was
+observed in production, so the legacy providers, their config/env keys, the weekly
+collector job and the parity report were all removed. Two consequences to carry:
+(1) `fundamental_data` now has no provider fallback — recovery is restore-from-backup;
+(2) disabling **SEC Fundamentals Import** stops the SEC fetch only, because the local
+cache refresh was deliberately moved outside the job-enable check. Remaining
+follow-up: delete the migration-029 tombstone rows once the rollback window closes.
 
 **Known caveats to carry (documented in the findings report, not bugs to fix):**
 - KLAC-class post-filing splits: P/E wrong until the next 10-Q; undetectable from