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>

.env.example

@@ -18,16 +18,9 @@ OPENAI_API_KEY=
 OPENAI_MODEL=gpt-4o-mini
 OPENAI_SENTIMENT_BATCH_SIZE=5
 
-# Fundamentals Provider — Financial Modeling Prep
-FMP_API_KEY=
-
-# Fundamentals Provider — Finnhub (optional fallback)
-FINNHUB_API_KEY=
-
-# Fundamentals Provider — Alpha Vantage (optional fallback)
-ALPHA_VANTAGE_API_KEY=
-
-# Dolt bulk data — local clone of post-no-preference/earnings (workstream A).
+# Dolt bulk data — local clone of post-no-preference/earnings. Together with the
+# SEC EDGAR block below this is the ONLY fundamentals source; there is no
+# provider-API fallback.
 # DOLT_BINARY: path to the dolt CLI (set the full path in dev if it's not on PATH,
 #   e.g. Windows: C:\Program Files\Dolt\bin\dolt.exe). DOLT_DATA_DIR holds the
 #   clones; in PRODUCTION it MUST be outside the deploy tree (deploy is
@@ -52,10 +45,6 @@ SEC_REQUEST_SPACING_SECONDS=0.2
 SEC_MAX_RETRIES=4
 SEC_REQUEST_TIMEOUT_SECONDS=30.0
 
-# A5 read-only parity report archive. In production keep this outside the
-# rsync deployment tree, e.g. /var/lib/signal-platform/reports/fundamentals-parity.
-FUNDAMENTALS_PARITY_REPORT_DIR=reports/fundamentals-parity
-
 # Regime Monitor — FRED (VIX + HY credit spreads). Free key: https://fred.stlouisfed.org/docs/api/api_key.html
 # Optional: without it the volatility (V1) and credit (C1) pillars show as n/a.
 FRED_API_KEY=
@@ -63,10 +52,7 @@ FRED_API_KEY=
 # Scheduled Jobs
 DATA_COLLECTOR_FREQUENCY=daily
 SENTIMENT_POLL_INTERVAL_MINUTES=30
-FUNDAMENTAL_FETCH_FREQUENCY=daily
 RR_SCAN_FREQUENCY=daily
-FUNDAMENTAL_RATE_LIMIT_RETRIES=3
-FUNDAMENTAL_RATE_LIMIT_BACKOFF_SECONDS=15
 
 # Scoring Defaults
 DEFAULT_WATCHLIST_AUTO_SIZE=10