feat(nodes): SSH bootstrap + housekeeping — install script, bundled binaries, auto-prune (#50)

* feat(nodes): SSH bootstrap + housekeeping — install script, bundled binaries, auto-prune

- `containr nodes add <user@host>` mints an enroll token, SSHes once,
  runs the install script remotely; --print emits the one-liner
- Public /api/agents/install.sh + /api/agents/download/{platform};
  agent binaries built into the image under /agents
- Agent-side `prune` (bounded docker system prune, volumes opt-in)
  and `system_df` commands
- node_agents.auto_prune + health sweep enqueues daily prune;
  offline/online transitions notify admins
- CLI nodes update/prune/commands + MCP tools (prune confirm-gated)
- Usage page: install one-liner, per-node Prune + auto toggle

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

* feat(nodes): node detail page — telemetry, containers, commands, controls

/nodes/:id (admin): cpu/mem sparklines from heartbeat history
(1h/24h/7d), containers on node, command history, inline rename,
auto-prune toggle, prune-now with volume opt-in, remove. Agent rows
on the Usage page link into it.

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

* feat(nodes): mesh awareness + node detail page

- agent reports tailscale/netbird/zerotier/wireguard interface IPs at
  register (authoritative — absent interfaces clear stored state)
- backend stores under node_agents.metadata.mesh, merged on re-register
- node detail page shows mesh addresses under the primary IP

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

---------

Co-authored-by: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

app/backend/cmd/agent/main.go

@@ -167,6 +167,8 @@ func register(ctx context.Context, client *http.Client, cfg agentConfig) (string
 		"ip_address":   cfg.IP,
 		"port":         cfg.Port,
 		"capabilities": detectCapabilities(),
+		// Always send mesh so a removed interface clears stored state.
+		"mesh": detectMeshInterfaces(),
 	}
 	var response registerResponse
 	if err := postJSON(ctx, client, cfg, "/api/agents/register", payload, &response); err != nil {
@@ -246,11 +248,29 @@ func executeCommand(item command) (string, error) {
 		return runDocker("restart", commandTarget(item.Payload))
 	case "remove_container":
 		return runDocker("rm", "-f", commandTarget(item.Payload))
+	case "prune":
+		return dockerPrune(item.Payload)
+	case "system_df":
+		return runDocker("system", "df", "--format", "json")
 	default:
 		return "", fmt.Errorf("unsupported command type %q", item.Type)
 	}
 }
 
+// dockerPrune runs a bounded docker system prune. Volumes are excluded
+// unless the payload explicitly opts in — a stray volume prune destroys
+// database data.
+func dockerPrune(payload map[string]interface{}) (string, error) {
+	args := []string{"system", "prune", "-af"}
+	if boolValue(payload["volumes"]) {
+		args = append(args, "--volumes")
+	}
+	if until := stringValue(payload["until"]); until != "" {
+		args = append(args, "--filter", fmt.Sprintf("until=%s", until))
+	}
+	return runDocker(args...)
+}
+
 func createContainer(payload map[string]interface{}) (string, error) {
 	container, ok := payload["container"].(map[string]interface{})
 	if !ok {
@@ -354,6 +374,42 @@ func detectCapabilities() capabilities {
 	}
 }
 
+// detectMeshInterfaces reports overlay-network interface IPs (tailscale,
+// netbird, zerotier, wireguard) so the backend can display reachable
+// mesh addresses alongside the primary IP.
+func detectMeshInterfaces() map[string]string {
+	ifaces, err := net.Interfaces()
+	if err != nil {
+		return nil
+	}
+	mesh := map[string]string{}
+	for _, iface := range ifaces {
+		name := strings.ToLower(iface.Name)
+		isMesh := strings.HasPrefix(name, "tailscale") || strings.HasPrefix(name, "ts.") ||
+			strings.HasPrefix(name, "netbird") || strings.HasPrefix(name, "wt") ||
+			strings.HasPrefix(name, "zt") || strings.HasPrefix(name, "wg")
+		if !isMesh || iface.Flags&net.FlagUp == 0 {
+			continue
+		}
+		addrs, err := iface.Addrs()
+		if err != nil {
+			continue
+		}
+		for _, addr := range addrs {
+			ip, _, err := net.ParseCIDR(addr.String())
+			if err != nil || ip.IsLoopback() {
+				continue
+			}
+			if v4 := ip.To4(); v4 != nil {
+				mesh[iface.Name] = v4.String()
+			} else if _, exists := mesh[iface.Name]; !exists {
+				mesh[iface.Name] = ip.String()
+			}
+		}
+	}
+	return mesh
+}
+
 func collectResources(ip string) nodeResources {
 	mem := readMemory()
 	storage := readStorage("/")