refactor(switches): standardize all switch names to <site>-<rack>-<function>-<NN>

Rename all 5 switches across all layers (DNS, DHCP, device hostname,
conman console, ser2net, udev symlinks, repo files) to follow the
<site>-<rack>-<function>-<count> convention:
  pfv-core-sw01    → pfv-r5-core-01     (rack 5 core)
  pfv-tor3-mgmt    → pfv-r3-tor-mgmt-01 (rack 3 mgmt TOR)
  pfv-tor3-stor    → pfv-r3-tor-stor-01 (rack 3 storage TOR)
  pfv-r2-tor-top   → pfv-r2-tor-01      (rack 2 TOR)
  subodev-torsw01  → pfv-r6-mgmt-01     (rack 6 mgmt)

Dead switch (pfv-r2-sw, port 2007) removed from mapping.txt.
pfv-rrinfra-rtr unchanged (router, not a switch).

Device hostnames changed via conman. Configs regenerated on pfv-tsys4.
All .cmds files, validate-conman.sh, and AGENTS.md updated. [#369]

💘 Generated with Crush

Assisted-by: Crush:glm-5.2

netinfra/dhcp/dhcpd-primary.conf

@@ -61,7 +61,7 @@ subnet 192.168.0.0 netmask 255.255.252.0 {
     hardware ethernet 00:0d:56:41:7a:4d;
     fixed-address 192.168.0.10;
   }
-  host pfv-core-sw01 {
+  host pfv-r5-core-01 {
     hardware ethernet a4:ba:db:6f:ce:28;
     fixed-address 192.168.0.12;
   }

netinfra/dhcp/dhcpd-secondary.conf

@@ -59,7 +59,7 @@ subnet 192.168.0.0 netmask 255.255.252.0 {
     hardware ethernet 00:0d:56:41:7a:4d;
     fixed-address 192.168.0.10;
   }
-  host pfv-core-sw01 {
+  host pfv-r5-core-01 {
     hardware ethernet a4:ba:db:6f:ce:28;
     fixed-address 192.168.0.12;
   }

netinfra/switches/pfv-r3-tor-stor-01-mac.cmds

@@ -1,4 +1,4 @@
-! pfv-tor3-stor — MAC table + port details (Dell PowerConnect 5324 commands)
+! pfv-r3-tor-stor-01 — MAC table + port details (Dell PowerConnect 5324 commands)
 enable
 show bridge addressing-table address
 show interfaces description

netinfra/switches/pfv-r3-tor-stor-01.cmds

@@ -1,4 +1,4 @@
-! pfv-tor3-stor — Neyland 24T (Radlan-based, rack 3 storage TOR)
+! pfv-r3-tor-stor-01 — Neyland 24T (Radlan-based, rack 3 storage TOR)
 ! Radlan CLI uses different keywords than DNOS
 enable
 show system

netinfra/switches/pfv-r5-core-01-mac.cmds

@@ -1,4 +1,4 @@
-! pfv-core-sw01 — MAC address table + LLDP neighbors
+! pfv-r5-core-01 — MAC address table + LLDP neighbors
 terminal datadump
 enable
 show mac-address-table

netinfra/switches/pfv-r5-core-01.cmds

@@ -1,4 +1,4 @@
-! pfv-core-sw01 — Dell PowerConnect 5448 (core switch, rack 5)
+! pfv-r5-core-01 — Dell PowerConnect 5448 (core switch, rack 5)
 ! Need running-config to diagnose ch1 port mismatch (g16 up but not in LAG, g17 down)
 terminal datadump
 enable