refactor: phase 0-2 MoFin architecture reform — single source of truth

Phase 0 (止血):
- mo_models.py: unified calc_total_assets(), is_hk_stock(), get_hk_rate() — single source of truth
- Fixed 3 files missing frozen_cash: holdings_reconciliation, server, import_holding_xls
- Fixed stale_push_wlin: unified is_hk_stock detection, removed hardcoded 0.866
- Fixed price_monitor: consolidated 2 duplicate total_assets blocks into mo_models calls
- Fixed stock_scorer: replaced broken len()<=5 is_hk_stock heuristic
- Fixed strategy_lifecycle: replaced non-existent currency_utils import with mo_models

Phase 1 (DSA adapter):
- mo_provider.py: wraps DSA DataFetcherManager (16 fetchers, auto-fallback)
  - TDX relay as primary, DSA as backup for realtime/kline/news/fundamentals

Phase 2 (Integration):
- mo_bridge.py: injects DSA market review + news context into MoFin analysis prompts
- Graceful degradation if DSA not installed

Infrastructure:
- mo_config.py: centralized Config singleton replacing scattered hardcoded paths
- All 11 changed files pass python compile check

Impact: total_assets now computed in ONE place (mo_models).
        is_hk_stock now ONE implementation (no more false negatives).
        HK rate now ONE source (hk_rate API → cache → 0.87 fallback).
        No more hardcoded 0.866/0.8664/0.8700 divergence.

server.py

@@ -957,7 +957,9 @@ def upload_confirm():
         if summary.get("total_assets"):
             existing["total_assets"] = float(summary["total_assets"])
         else:
-            existing["total_assets"] = existing["stock_value"] + existing.get("cash", 0)
+            # Use unified formula (includes frozen_cash)
+            from mo_models import calc_total_assets
+            existing["total_assets"] = calc_total_assets(existing)
         if summary.get("day_pnl"):
             existing["day_pnl"] = float(summary["day_pnl"])
         existing["updated_at"] = datetime.now().isoformat()