fix: remove HL-delisted coins from scanner (BNT/CATI/CYBER/ILV/LISTA/OGN/STG) + PIXEL

Root cause: HL WS uses allMids (all coins), BG WS subscribes per-coin.
Delisted coins had stale HL prices showing huge fake spreads (~200%).
Monitor tried entry → BG buy succeeds, HL sell fails (Trading is halted)
→ orphan position on BG accumulated across restarts.

Fix:
- Set HL="" for BNT, CATI, CYBER, ILV, LISTA, OGN, STG, PIXEL
- Add guard in ScanBGHL to skip coins where BG or HL is empty
- Same guard in SpreadWindowTracker.Tick

types.go

@@ -142,6 +142,9 @@ func NewSpreadWindowTracker() *SpreadWindowTracker {
 func (swt *SpreadWindowTracker) Tick(snap map[string]map[string]float64, threshold float64) {
 	now := time.Now()
 	for _, coin := range TrackedCoins {
+		if coin.BG == "" || coin.HL == "" {
+			continue
+		}
 		exMap := snap[coin.Name]
 		if exMap == nil {
 			continue