feat(proxmox): add LXC container stats endpoint with streaming support

Implement a new API endpoint to retrieve real-time statistics for Proxmox
LXC containers, similar to `docker stats` functionality.

Changes:
- Add `GET /api/v1/proxmox/stats/:node/:vmid` endpoint with HTTP and WebSocket support
- Implement resource polling loop to cache VM metadata every 3 seconds
- Create `LXCStats()` method with streaming (websocket) and single-shot modes
- Format output as: STATUS|CPU%|MEM USAGE/LIMIT|MEM%|NET I/O|BLOCK I/O
- Add `GetResource()` method for efficient VM resource lookup by kind and ID
- Fix task creation bug using correct client reference

Example response:
  running|31.1%|9.6GiB/20GiB|48.87%|4.7GiB/3.3GiB|25GiB/36GiB

internal/proxmox/node.go

@@ -6,7 +6,6 @@ import (
 	"strings"
 
 	"github.com/bytedance/sonic"
-	"github.com/luthermonson/go-proxmox"
 	"github.com/yusing/goutils/pool"
 )
 
@@ -19,11 +18,22 @@ type NodeConfig struct {
 type Node struct {
 	name   string
 	id     string // likely node/<name>
-	client *proxmox.Client
+	client *Client
+
+	// statsScriptInitErrs *xsync.Map[int, error]
 }
 
 var Nodes = pool.New[*Node]("proxmox_nodes")
 
+func NewNode(client *Client, name, id string) *Node {
+	return &Node{
+		name:   name,
+		id:     id,
+		client: client,
+		// statsScriptInitErrs: xsync.NewMap[int, error](xsync.WithGrowOnly()),
+	}
+}
+
 func AvailableNodeNames() string {
 	if Nodes.Size() == 0 {
 		return ""