fix(filter): deprioritize recent movers instead of dropping, exempt mean_reversion pipeline

- Change recent_mover_action default from "filter" to "deprioritize" so candidates
  that moved >10% in the past 7 days reach the ranker (with lowered priority + context
  annotation) rather than being silently dropped
- Exempt mean_reversion pipeline candidates (rsi_oversold) from the recent-mover action
  entirely — stocks that pulled back hard are the signal, not a disqualifier
- Hoist SCANNER_REGISTRY import to module level (removes duplicate inline imports)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tradingagents/dataflows/discovery/filter.py

@@ -8,6 +8,7 @@ import pandas as pd
 from tradingagents.dataflows.data_cache.ohlcv_cache import download_ohlcv_cached
 from tradingagents.dataflows.discovery.candidate import Candidate
 from tradingagents.dataflows.discovery.discovery_config import DiscoveryConfig
+from tradingagents.dataflows.discovery.scanner_registry import SCANNER_REGISTRY
 from tradingagents.dataflows.discovery.utils import (
     PRIORITY_ORDER,
     Strategy,
@@ -479,7 +480,6 @@ class CandidateFilter:
 
                         if reaction.get("status") == "lagging":
                             # Mean-reversion candidates are expected to have moved — exempt them
-                            from tradingagents.dataflows.discovery.scanner_registry import SCANNER_REGISTRY
                             source = cand.get("source", "")
                             scanner_cls = SCANNER_REGISTRY.scanners.get(source)
                             scanner_pipeline = getattr(scanner_cls, "pipeline", None)
@@ -979,8 +979,6 @@ class CandidateFilter:
 
     def _assign_strategy(self, cand: Dict[str, Any]):
         """Assign strategy by looking up the scanner's declared strategy from the registry."""
-        from tradingagents.dataflows.discovery.scanner_registry import SCANNER_REGISTRY
-
         source = cand.get("source", "")
         scanner_class = SCANNER_REGISTRY.scanners.get(source)
         if scanner_class and getattr(scanner_class, "strategy", None):