feat: add CLI commands for mock mode management

New commands:
  pulse mock enable   - Enable mock mode
  pulse mock disable  - Disable mock mode
  pulse mock status   - Show current status

Makes it easy to toggle between mock and real data without
manually editing config files.

cmd/pulse/mock.go

@@ -0,0 +1,242 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/spf13/cobra"
+)
+
+var mockCmd = &cobra.Command{
+	Use:   "mock",
+	Short: "Manage mock/demo mode for development and demos",
+	Long:  `Enable or disable mock mode to run Pulse with simulated data instead of real infrastructure.`,
+}
+
+var mockEnableCmd = &cobra.Command{
+	Use:   "enable",
+	Short: "Enable mock mode with simulated infrastructure data",
+	Long: `Enable mock mode to run Pulse with simulated data.
+
+This creates/updates the mock.env file and requires a service restart.
+Mock mode is useful for:
+  - Demos without real infrastructure
+  - Development and testing
+  - Showcasing AI patrol features
+
+Example:
+  pulse mock enable
+  sudo systemctl restart pulse`,
+	Run: func(cmd *cobra.Command, args []string) {
+		if err := setMockMode(true); err != nil {
+			fmt.Fprintf(os.Stderr, "Error: %v\n", err)
+			os.Exit(1)
+		}
+		fmt.Println("✓ Mock mode enabled")
+		fmt.Println("")
+		fmt.Println("Restart Pulse to apply changes:")
+		fmt.Println("  sudo systemctl restart pulse")
+	},
+}
+
+var mockDisableCmd = &cobra.Command{
+	Use:   "disable",
+	Short: "Disable mock mode and use real infrastructure",
+	Long: `Disable mock mode to reconnect to real infrastructure.
+
+This updates the mock.env file and requires a service restart.
+
+Example:
+  pulse mock disable
+  sudo systemctl restart pulse`,
+	Run: func(cmd *cobra.Command, args []string) {
+		if err := setMockMode(false); err != nil {
+			fmt.Fprintf(os.Stderr, "Error: %v\n", err)
+			os.Exit(1)
+		}
+		fmt.Println("✓ Mock mode disabled")
+		fmt.Println("")
+		fmt.Println("Restart Pulse to apply changes:")
+		fmt.Println("  sudo systemctl restart pulse")
+	},
+}
+
+var mockStatusCmd = &cobra.Command{
+	Use:   "status",
+	Short: "Show current mock mode status",
+	Run: func(cmd *cobra.Command, args []string) {
+		enabled, config := getMockStatus()
+		if enabled {
+			fmt.Println("Mock mode: ENABLED")
+			fmt.Println("")
+			fmt.Println("Configuration:")
+			for _, line := range config {
+				fmt.Printf("  %s\n", line)
+			}
+		} else {
+			fmt.Println("Mock mode: DISABLED")
+			fmt.Println("")
+			fmt.Println("Run 'pulse mock enable' to enable mock mode")
+		}
+	},
+}
+
+func init() {
+	mockCmd.AddCommand(mockEnableCmd)
+	mockCmd.AddCommand(mockDisableCmd)
+	mockCmd.AddCommand(mockStatusCmd)
+	rootCmd.AddCommand(mockCmd)
+}
+
+// getMockEnvPath returns the path to mock.env
+func getMockEnvPath() string {
+	// Check PULSE_DATA_DIR first, then fall back to /opt/pulse
+	dataDir := os.Getenv("PULSE_DATA_DIR")
+	if dataDir == "" {
+		// Check if we're in development (running from /opt/pulse)
+		if _, err := os.Stat("/opt/pulse/mock.env"); err == nil {
+			return "/opt/pulse/mock.env"
+		}
+		dataDir = "/opt/pulse"
+	}
+	return filepath.Join(dataDir, "mock.env")
+}
+
+// setMockMode enables or disables mock mode by updating mock.env
+func setMockMode(enable bool) error {
+	envPath := getMockEnvPath()
+
+	// Read existing config or create default
+	config := getDefaultMockConfig()
+
+	// Try to preserve existing config
+	if data, err := os.ReadFile(envPath); err == nil {
+		existing := parseMockEnv(string(data))
+		for k, v := range existing {
+			if k != "PULSE_MOCK_MODE" {
+				config[k] = v
+			}
+		}
+	}
+
+	// Set the mode
+	if enable {
+		config["PULSE_MOCK_MODE"] = "true"
+	} else {
+		config["PULSE_MOCK_MODE"] = "false"
+	}
+
+	// Write the file
+	return writeMockEnv(envPath, config)
+}
+
+// getDefaultMockConfig returns the default mock configuration
+func getDefaultMockConfig() map[string]string {
+	return map[string]string{
+		"PULSE_MOCK_MODE":              "false",
+		"PULSE_MOCK_NODES":             "7",
+		"PULSE_MOCK_VMS_PER_NODE":      "5",
+		"PULSE_MOCK_LXCS_PER_NODE":     "8",
+		"PULSE_MOCK_DOCKER_HOSTS":      "3",
+		"PULSE_MOCK_DOCKER_CONTAINERS": "12",
+		"PULSE_MOCK_GENERIC_HOSTS":     "4",
+		"PULSE_MOCK_K8S_CLUSTERS":      "2",
+		"PULSE_MOCK_K8S_NODES":         "4",
+		"PULSE_MOCK_K8S_PODS":          "30",
+		"PULSE_MOCK_K8S_DEPLOYMENTS":   "12",
+		"PULSE_MOCK_RANDOM_METRICS":    "true",
+		"PULSE_MOCK_STOPPED_PERCENT":   "20",
+	}
+}
+
+// parseMockEnv parses a mock.env file into a map
+func parseMockEnv(content string) map[string]string {
+	result := make(map[string]string)
+	for _, line := range strings.Split(content, "\n") {
+		line = strings.TrimSpace(line)
+		if line == "" || strings.HasPrefix(line, "#") {
+			continue
+		}
+		parts := strings.SplitN(line, "=", 2)
+		if len(parts) == 2 {
+			result[parts[0]] = parts[1]
+		}
+	}
+	return result
+}
+
+// writeMockEnv writes the mock.env file
+func writeMockEnv(path string, config map[string]string) error {
+	// Order keys for consistent output
+	keys := []string{
+		"PULSE_MOCK_MODE",
+		"PULSE_MOCK_NODES",
+		"PULSE_MOCK_VMS_PER_NODE",
+		"PULSE_MOCK_LXCS_PER_NODE",
+		"PULSE_MOCK_DOCKER_HOSTS",
+		"PULSE_MOCK_DOCKER_CONTAINERS",
+		"PULSE_MOCK_GENERIC_HOSTS",
+		"PULSE_MOCK_K8S_CLUSTERS",
+		"PULSE_MOCK_K8S_NODES",
+		"PULSE_MOCK_K8S_PODS",
+		"PULSE_MOCK_K8S_DEPLOYMENTS",
+		"PULSE_MOCK_RANDOM_METRICS",
+		"PULSE_MOCK_STOPPED_PERCENT",
+	}
+
+	var lines []string
+	lines = append(lines, "# Pulse Mock Mode Configuration")
+	lines = append(lines, "# Enable with: pulse mock enable")
+	lines = append(lines, "# Disable with: pulse mock disable")
+	lines = append(lines, "")
+
+	for _, key := range keys {
+		if val, ok := config[key]; ok {
+			lines = append(lines, fmt.Sprintf("%s=%s", key, val))
+		}
+	}
+
+	// Add any extra keys not in our ordered list
+	for k, v := range config {
+		found := false
+		for _, key := range keys {
+			if k == key {
+				found = true
+				break
+			}
+		}
+		if !found {
+			lines = append(lines, fmt.Sprintf("%s=%s", k, v))
+		}
+	}
+
+	content := strings.Join(lines, "\n") + "\n"
+	return os.WriteFile(path, []byte(content), 0644)
+}
+
+// getMockStatus returns the current mock mode status and config
+func getMockStatus() (enabled bool, config []string) {
+	envPath := getMockEnvPath()
+
+	data, err := os.ReadFile(envPath)
+	if err != nil {
+		return false, nil
+	}
+
+	parsed := parseMockEnv(string(data))
+	enabled = parsed["PULSE_MOCK_MODE"] == "true"
+
+	if enabled {
+		config = []string{
+			fmt.Sprintf("Nodes: %s", parsed["PULSE_MOCK_NODES"]),
+			fmt.Sprintf("VMs per node: %s", parsed["PULSE_MOCK_VMS_PER_NODE"]),
+			fmt.Sprintf("Containers per node: %s", parsed["PULSE_MOCK_LXCS_PER_NODE"]),
+			fmt.Sprintf("Docker hosts: %s", parsed["PULSE_MOCK_DOCKER_HOSTS"]),
+			fmt.Sprintf("K8s clusters: %s", parsed["PULSE_MOCK_K8S_CLUSTERS"]),
+		}
+	}
+
+	return enabled, config
+}

mock.env

@@ -1,4 +1,8 @@
-PULSE_MOCK_MODE=false
+# Pulse Mock Mode Configuration
+# Enable with: pulse mock enable
+# Disable with: pulse mock disable
+
+PULSE_MOCK_MODE=true
 PULSE_MOCK_NODES=7
 PULSE_MOCK_VMS_PER_NODE=5
 PULSE_MOCK_LXCS_PER_NODE=8