fix: ops pipeline — rate limit, validation cycle, snapshots, config query, rejection reason

- Polygon rate limit env-configurable, default 5 (free tier)
- v3_engine_enabled reads from JSONB config column correctly
- Validation cycle (outcome eval + metrics) wired into scheduler hourly
- Daily portfolio/risk snapshots after 16:30 ET with idempotency
- Prediction snapshot price fallback from positions table
- Order rejection_reason + rejected_at persisted on insert
- Lake-publisher scaled to 0 replicas (redundant)
- Test fix: isolate per-type rate limit tests from Polygon global

services/validation/prediction_snapshot.py

@@ -311,7 +311,19 @@ async def create_prediction_snapshot(
     # 1. Fetch prices — handle NULL gracefully (Requirement 1.5)
     ticker_price = await fetch_latest_close_price(pool, ticker)
     if ticker_price is None:
-        logger.warning("No market price available for %s at snapshot time", ticker)
+        # Fallback: try positions table for tickers we actively hold (Bug 1.8)
+        pos_row = await pool.fetchrow(
+            "SELECT current_price FROM positions "
+            "WHERE ticker = $1 AND current_price IS NOT NULL LIMIT 1",
+            ticker,
+        )
+        if pos_row:
+            ticker_price = float(pos_row["current_price"])
+            logger.info(
+                "Used positions fallback price for %s: %s", ticker, ticker_price
+            )
+        else:
+            logger.warning("No market price available for %s at snapshot time", ticker)
 
     spy_price = await fetch_latest_close_price(pool, "SPY")
     if spy_price is None: