feat: add 802.1X switch access policy support

- Add meraki_switch_access_policy resource to module (multi-auth, critical VLAN)
- Add meraki_switch_port resource for per-port policy assignment
- Add switch_access_policies and switch_port_configs variables to module and site
- Create switch.auto.tfvars for BCN01-LAB with 802.1X-CORPO policy
  (RADIUS: 15.15.15.15:1912, critical VLAN: 100, host_mode: Multi-Auth)
- switch_port_configs starts empty; add serial + port_id to assign policy to ports

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

sites/BCN01-LAB/main.tf

@@ -23,10 +23,12 @@ provider "meraki" {}
 module "bcn01_lab" {
   source = "../../modules/meraki-site"
 
-  organization_name = var.organization_name
-  network_name      = var.network_name
-  switch_vlans      = var.switch_vlans
-  firewall_rules    = var.firewall_rules
-  wireless_ssids    = var.wireless_ssids
-  radius_secret     = var.radius_secret
+  organization_name      = var.organization_name
+  network_name           = var.network_name
+  switch_vlans           = var.switch_vlans
+  firewall_rules         = var.firewall_rules
+  wireless_ssids         = var.wireless_ssids
+  radius_secret          = var.radius_secret
+  switch_access_policies = var.switch_access_policies
+  switch_port_configs    = var.switch_port_configs
 }