refactor(proxmox): consolidate NodeConfig and add service field

Centralize Proxmox node configuration by moving `ProxmoxConfig` from `internal/types/idlewatcher.go` to a new `NodeConfig` struct in `internal/proxmox/node.go`.

- Add `proxmox` field to route; allowing `proxy.app.proxmox` labels and corresponding route file config
- Added `service` optional field to NodeConfig for service identification
- Integrated Proxmox config directly into Route struct with proper validation
- Propagate Proxmox settings to Idlewatcher during route validation
- Updated swagger documentation to reflect schema changes

internal/api/v1/docs/swagger.yaml

@@ -641,7 +641,7 @@ definitions:
       no_loading_page:
         type: boolean
       proxmox:
-        $ref: '#/definitions/ProxmoxConfig'
+        $ref: '#/definitions/ProxmoxNodeConfig'
       start_endpoint:
         description: Optional path that must be hit to start container
         type: string
@@ -933,10 +933,12 @@ definitions:
     - ProviderTypeDocker
     - ProviderTypeFile
     - ProviderTypeAgent
-  ProxmoxConfig:
+  ProxmoxNodeConfig:
     properties:
       node:
         type: string
+      service:
+        type: string
       vmid:
         type: integer
     required:
@@ -1050,6 +1052,10 @@ definitions:
         description: for backward compatibility
         type: string
         x-nullable: true
+      proxmox:
+        allOf:
+        - $ref: '#/definitions/ProxmoxNodeConfig'
+        x-nullable: true
       purl:
         type: string
       response_header_timeout:
@@ -1849,6 +1855,10 @@ definitions:
         description: for backward compatibility
         type: string
         x-nullable: true
+      proxmox:
+        allOf:
+        - $ref: '#/definitions/ProxmoxNodeConfig'
+        x-nullable: true
       purl:
         type: string
       response_header_timeout: