refactor: replace REST API with Unix socket IPC + CLI subcommands

- Remove insecure HTTP API endpoints (positions, close, close-all, pnl)
- Add Unix socket IPC at /tmp/exchange-monitor.sock
- Add CLI subcommands: status, close-all, close <COIN>, stop, start
- Bind dashboard HTTP to 127.0.0.1:8888 (localhost only)

main.go

@@ -18,6 +18,25 @@ import (
 )
 
 func main() {
+	// CLI subcommand mode: talk to running daemon via IPC
+	if len(os.Args) > 1 {
+		switch os.Args[1] {
+		case "status", "close-all", "stop", "start":
+			runIPCClient(os.Args[1], "")
+		case "close":
+			if len(os.Args) < 3 {
+				fmt.Fprintln(os.Stderr, "Usage: exchange-monitor close <COIN>")
+				os.Exit(1)
+			}
+			runIPCClient("close", os.Args[2])
+		default:
+			fmt.Fprintf(os.Stderr, "Unknown command: %s\n", os.Args[1])
+			fmt.Fprintln(os.Stderr, "Commands: status, close-all, close <COIN>, stop, start")
+			os.Exit(1)
+		}
+		return
+	}
+
 	log.SetFlags(log.Ldate | log.Ltime | log.Lshortfile)
 
 	// Set up multi-writer: stdout + log file
@@ -52,8 +71,11 @@ func main() {
 	// Initialize trader
 	trader := NewTrader(cfg, database)
 
-	// Initialize dashboard (web server + SSE)
-	dashboard := NewDashboard(store, trader, database, ":8888")
+	// Start Unix socket IPC for CLI commands
+	trader.startIPCServer()
+
+	// Initialize dashboard (web server + SSE) — localhost only for security
+	dashboard := NewDashboard(store, trader, database, "127.0.0.1:8888")
 	go dashboard.Run()
 
 	// Spread window tracker — measures how long spreads stay above threshold