feat: auto-install pulumi cli and adjust ssh retry configuration

- Auto-install Pulumi CLI when not found instead of returning error
- Add installed binary to PATH for immediate availability
- Update SSH pool retry config to 5 attempts with 10s fixed delays
- Improve user feedback with progress indicators

internal/cloud/pulumi.go

@@ -169,5 +169,25 @@ func ensurePulumiInstalled() error {
 		}
 	}
 
-	return fmt.Errorf("pulumi CLI not found - install via: curl -fsSL https://get.pulumi.com | sh")
+	// Auto-install Pulumi CLI
+	fmt.Println("  ▷ Pulumi CLI not found, installing automatically...")
+	installCmd := exec.Command("bash", "-c", "curl -fsSL https://get.pulumi.com | sh")
+	installCmd.Stdout = os.Stdout
+	installCmd.Stderr = os.Stderr
+	if err := installCmd.Run(); err != nil {
+		return fmt.Errorf("failed to install pulumi CLI: %w", err)
+	}
+
+	// Add the installed pulumi to PATH
+	pulumiPath := filepath.Join(os.Getenv("HOME"), ".pulumi", "bin", "pulumi")
+	if _, err := os.Stat(pulumiPath); err == nil {
+		currentPath := os.Getenv("PATH")
+		if err := os.Setenv("PATH", filepath.Dir(pulumiPath)+":"+currentPath); err != nil {
+			return fmt.Errorf("failed to set PATH: %w", err)
+		}
+		fmt.Println("  ✓ Pulumi CLI installed successfully")
+		return nil
+	}
+
+	return fmt.Errorf("pulumi CLI installation completed but binary not found at %s", pulumiPath)
 }

internal/runner/ssh_pool.go

@@ -143,10 +143,10 @@ func (p *SSHPool) Get(ctx context.Context, config *core.RunnerConfig) (*ssh.Clie
 	addr := fmt.Sprintf("%s:%d", config.Host, port)
 	var client *ssh.Client
 	err = retry.Do(ctx, retry.Config{
-		MaxAttempts:  3,
-		InitialDelay: 500 * time.Millisecond,
-		MaxDelay:     5 * time.Second,
-		Multiplier:   2.0,
+		MaxAttempts:  5,
+		InitialDelay: 10 * time.Second,
+		MaxDelay:     10 * time.Second,
+		Multiplier:   1.0,
 	}, func() error {
 		var dialErr error
 		client, dialErr = ssh.Dial("tcp", addr, sshConfig)