TUI: async polling off UI thread, 5s SSH hard timeout + remote cooldown, at-most-one-fetch, ? help menu

state.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"context"
 	"encoding/json"
 	"fmt"
 	"os"
@@ -275,15 +276,25 @@ func readRemoteStates(cfg RemoteConfig) ([]AgentState, error) {
 		remotePath = filepath.Join(home, ".pi", "agent", "dashboard")
 	}
 
-	// SSH in, cat all JSON files
-	cmd := exec.Command("ssh",
-		"-o", "ConnectTimeout=5",
+	// SSH in, cat all JSON files. Hard 5s overall timeout (CommandContext)
+	// plus a 3s connect timeout — a slow or hung remote must never block the
+	// dashboard or leave ssh processes accumulating.
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	cmd := exec.CommandContext(ctx, "ssh",
+		"-o", "ConnectTimeout=3",
 		"-o", "BatchMode=yes",
+		"-o", "ServerAliveInterval=5",
+		"-o", "ServerAliveCountMax=1",
 		fmt.Sprintf("%s@%s", user, hostPort),
 		fmt.Sprintf("cat %s/*.json 2>/dev/null || true", remotePath),
 	)
 	output, err := cmd.Output()
 	if err != nil {
+		if ctx.Err() == context.DeadlineExceeded {
+			return nil, fmt.Errorf("ssh %s: timeout after 5s", cfg.Host)
+		}
 		return nil, fmt.Errorf("ssh %s: %w", cfg.Host, err)
 	}