fix config.json boolean fields (test_mode, trade_enabled) not applying

loadJSONConfig only checked != 0 for floats, missing bool overrides.
Added def.X = cfg.X || def.X for both booleans.

config.go

@@ -146,5 +146,11 @@ func loadJSONConfig() jsonConfig {
 		def.MockSlippagePct = cfg.MockSlippagePct
 	}
 
+	// Boolean fields: zero default is false, so use OR logic
+	// When JSON has true → true || false = true (override)
+	// When JSON has false → false || false = false (keep default)
+	def.TestMode = cfg.TestMode || def.TestMode
+	def.TradeEnabled = cfg.TradeEnabled || def.TradeEnabled
+
 	return def
 }