P2.2-P2.9, P3.2-P3.10, P4.1-P4.3: Complete Phases 2, 3, and 4

11 work units built in parallel and merged:

Agent handlers (Phase 2):
- P2.2 Deploy: pull images, stop/remove/run containers, update registry
- P2.3 Lifecycle: stop/start/restart with desired_state tracking
- P2.4 Status: list (registry), live check (runtime), get status (drift+events)
- P2.5 Sync: receive desired state, reconcile unmanaged containers
- P2.6 File transfer: push/pull scoped to /srv/<service>/, path validation
- P2.7 Adopt: match <service>-* containers, derive component names
- P2.8 Monitor: continuous watch loop, drift/flap alerting, event pruning
- P2.9 Snapshot: VACUUM INTO database backup command

CLI commands (Phase 3):
- P3.2 Login, P3.3 Deploy, P3.4 Stop/Start/Restart
- P3.5 List/Ps/Status, P3.6 Sync, P3.7 Adopt
- P3.8 Service show/edit/export, P3.9 Push/Pull, P3.10 Node list/add/remove

Deployment artifacts (Phase 4):
- Systemd units (agent service + backup timer)
- Example configs (CLI + agent)
- Install script (idempotent)

All packages: build, vet, lint (0 issues), test (all pass).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

cmd/mcp/node.go

@@ -2,7 +2,12 @@ package main
 
 import (
 	"fmt"
+	"os"
+	"text/tabwriter"
 
+	toml "github.com/pelletier/go-toml/v2"
+
+	"git.wntrmute.dev/kyle/mcp/internal/config"
 	"github.com/spf13/cobra"
 )
 
@@ -15,29 +20,112 @@ func nodeCmd() *cobra.Command {
 	list := &cobra.Command{
 		Use:   "list",
 		Short: "List registered nodes",
-		RunE: func(cmd *cobra.Command, args []string) error {
-			return fmt.Errorf("not implemented")
-		},
+		RunE:  runNodeList,
 	}
 
 	add := &cobra.Command{
 		Use:   "add <name> <address>",
 		Short: "Register a node",
 		Args:  cobra.ExactArgs(2),
-		RunE: func(cmd *cobra.Command, args []string) error {
-			return fmt.Errorf("not implemented")
-		},
+		RunE:  runNodeAdd,
 	}
 
 	remove := &cobra.Command{
 		Use:   "remove <name>",
 		Short: "Deregister a node",
 		Args:  cobra.ExactArgs(1),
-		RunE: func(cmd *cobra.Command, args []string) error {
-			return fmt.Errorf("not implemented")
-		},
+		RunE:  runNodeRemove,
 	}
 
 	cmd.AddCommand(list, add, remove)
 	return cmd
 }
+
+func runNodeList(_ *cobra.Command, _ []string) error {
+	cfg, err := config.LoadCLIConfig(cfgPath)
+	if err != nil {
+		return fmt.Errorf("load config: %w", err)
+	}
+
+	w := tabwriter.NewWriter(os.Stdout, 0, 4, 2, ' ', 0)
+	_, _ = fmt.Fprintln(w, "NAME\tADDRESS")
+	for _, n := range cfg.Nodes {
+		_, _ = fmt.Fprintf(w, "%s\t%s\n", n.Name, n.Address)
+	}
+	return w.Flush()
+}
+
+func runNodeAdd(_ *cobra.Command, args []string) error {
+	cfg, err := config.LoadCLIConfig(cfgPath)
+	if err != nil {
+		return fmt.Errorf("load config: %w", err)
+	}
+
+	name := args[0]
+	address := args[1]
+
+	for _, n := range cfg.Nodes {
+		if n.Name == name {
+			return fmt.Errorf("node %q already exists", name)
+		}
+	}
+
+	cfg.Nodes = append(cfg.Nodes, config.NodeConfig{
+		Name:    name,
+		Address: address,
+	})
+
+	if err := writeConfig(cfgPath, cfg); err != nil {
+		return fmt.Errorf("write config: %w", err)
+	}
+
+	fmt.Printf("Added node %s (%s)\n", name, address)
+	return nil
+}
+
+func runNodeRemove(_ *cobra.Command, args []string) error {
+	cfg, err := config.LoadCLIConfig(cfgPath)
+	if err != nil {
+		return fmt.Errorf("load config: %w", err)
+	}
+
+	name := args[0]
+
+	var found bool
+	nodes := make([]config.NodeConfig, 0, len(cfg.Nodes))
+	for _, n := range cfg.Nodes {
+		if n.Name == name {
+			found = true
+			continue
+		}
+		nodes = append(nodes, n)
+	}
+
+	if !found {
+		return fmt.Errorf("node %q not found", name)
+	}
+
+	cfg.Nodes = nodes
+
+	if err := writeConfig(cfgPath, cfg); err != nil {
+		return fmt.Errorf("write config: %w", err)
+	}
+
+	fmt.Printf("Removed node %s\n", name)
+	return nil
+}
+
+// writeConfig serializes the CLIConfig to TOML and writes it back to the
+// config file.
+func writeConfig(path string, cfg *config.CLIConfig) error {
+	data, err := toml.Marshal(cfg)
+	if err != nil {
+		return fmt.Errorf("marshal config: %w", err)
+	}
+
+	if err := os.WriteFile(path, data, 0o600); err != nil {
+		return fmt.Errorf("write config %q: %w", path, err)
+	}
+
+	return nil
+}