feat(tickers): record delisting instead of deleting the symbol

Retiring a symbol meant delete_ticker or bootstrap_universe(prune_missing),
both of which cascade through OHLCV, setups and scores. That destroys exactly
the history four research documents already apologise for: today's tracked
universe projected backward is survivorship-biased, and hard-deleting every
delisted name is what causes it. Keeping the rows preserves the option to fix
that — it does not fix it, which needs the replay to model a delisting as an
exit event.

tickers gains delisted_on / delisted_reason (migration 032). NULL means
actively traded.

The filter is opt-in via ticker_service.active_only rather than folded into a
shared getter: the registry and admin views deliberately keep delisted rows so
the delisting is visible, and a silent default would undo that. Applied to the
live path only — scanner, momentum ranking, scoring, breadth, fundamentals
candidates, SEC universe, earnings import, ingestion loops. run_backtest keeps
them on purpose.

Detection runs off OHLCV staleness, not off the SEC fundamentals import: that
importer stalls for days on unrelated Company-Facts gaps and would take
detection down with it. On a stale symbol the scheduler asks SEC for a Form
25/25-NSE/15 and retires it only on a hit, so a halt or a rename (SATS->ECHO)
keeps the existing warning. The probe waits 3 stale days so a market-data
outage cannot turn into one SEC request per symbol per run.

Safe to automate because it is reversible: clear_delisted un-retires a false
positive, where a delete had already taken the history.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

app/scheduler.py

@@ -66,6 +66,7 @@ from app.services.event_study_service import run_and_store as run_event_study_an
 from app.services.outcome_service import evaluate_pending_setups
 from app.services.rr_scanner_service import scan_all_tickers
 from app.services.sentiment_provider_service import build_sentiment_provider
+from app.services import ticker_service
 from app.services.ticker_universe_service import bootstrap_universe
 
 logger = logging.getLogger(__name__)
@@ -396,8 +397,10 @@ async def _is_job_enabled(db: AsyncSession, job_name: str) -> bool:
 
 
 async def _get_all_tickers(db: AsyncSession) -> list[str]:
-    """Return all tracked ticker symbols sorted alphabetically."""
-    result = await db.execute(select(Ticker.symbol).order_by(Ticker.symbol))
+    """Return all actively-traded ticker symbols sorted alphabetically."""
+    result = await db.execute(
+        ticker_service.active_only(select(Ticker.symbol).order_by(Ticker.symbol))
+    )
     return list(result.scalars().all())
 
 
@@ -412,8 +415,10 @@ async def _get_ohlcv_priority_tickers(db: AsyncSession) -> list[str]:
     latest_date = func.max(OHLCVRecord.date)
     missing_first = case((latest_date.is_(None), 0), else_=1)
     result = await db.execute(
-        select(Ticker.symbol)
-        .outerjoin(OHLCVRecord, OHLCVRecord.ticker_id == Ticker.id)
+        ticker_service.active_only(
+            select(Ticker.symbol)
+            .outerjoin(OHLCVRecord, OHLCVRecord.ticker_id == Ticker.id)
+        )
         .group_by(Ticker.id, Ticker.symbol)
         .order_by(missing_first.asc(), latest_date.asc(), Ticker.symbol.asc())
     )
@@ -662,14 +667,34 @@ async def collect_ohlcv(
                     _runtime_progress(job_name, processed=processed, total=total, current_ticker=symbol)
                     _log_event(logging.INFO, "ticker_collected", job=job_name, ticker=symbol, status=result.status, records=result.records_ingested)
                     if result.status == "stale":
-                        await _record_system_event(
-                            severity="warning",
-                            source=job_name,
-                            code="ohlcv_stale",
-                            message=result.message or f"No new OHLCV bars for {symbol}",
-                            symbol=symbol,
-                            dedup_key=f"ohlcv_stale:{symbol}",
+                        # "No new bars" cannot distinguish a delisting from a halt
+                        # or a rename, so ask SEC before warning again. A confirmed
+                        # delisting retires the symbol (keeping its history) and
+                        # ends the alert; anything unproven keeps warning.
+                        delisted_on = await ticker_service.confirm_delisting(
+                            db, symbol, last_bar=result.last_date
                         )
+                        if delisted_on is not None:
+                            await _record_system_event(
+                                severity="info",
+                                source=job_name,
+                                code="ticker_delisted",
+                                message=(
+                                    f"{symbol} delisted on {delisted_on} (SEC Form 25/15). "
+                                    "Retired from signals; price history retained."
+                                ),
+                                symbol=symbol,
+                                dedup_key=f"ticker_delisted:{symbol}",
+                            )
+                        else:
+                            await _record_system_event(
+                                severity="warning",
+                                source=job_name,
+                                code="ohlcv_stale",
+                                message=result.message or f"No new OHLCV bars for {symbol}",
+                                symbol=symbol,
+                                dedup_key=f"ohlcv_stale:{symbol}",
+                            )
                     if result.status == "partial":
                         # Rate limited — stop and resume next run
                         _log_event(logging.WARNING, "rate_limited", job=job_name, ticker=symbol, processed=processed)