feat(freeradius): implement node pinning and dynamic IP allocation

- add node pinning logic in authorize (reject if wrong node)
- optimize SQL queries using control variables
- assign Pool-Name dynamically for engineers
- integrate sqlippool for dynamic IP allocation (engineers only)
- add Session-Timeout aligned with lease_duration
- fix duplicate sqlippool execution in post-auth/accounting
- configure sqlippool with NAS-IP scoping for multi-node isolation

Ensures correct routing, tenant isolation, and scalable IP management.

files/mods-available/sqlippool

@@ -30,7 +30,7 @@ sqlippool {
         #  That way the NAS will automatically kick the user offline when the
         #  lease expires.
         #
-        lease_duration = 86400
+        lease_duration = 18000
 
         #
         # Timeout between each consecutive 'allocate_clear' queries (default: 1s)
@@ -76,7 +76,7 @@ sqlippool {
         # pool_key = "%{NAS-Port}"
         # pool_key = "%{Calling-Station-Id}"
         pool_key = "%{User-Name}"
-
+        nas_ip_address = "%{NAS-IP-Address}"
         ################################################################
         #
         #  WARNING: MySQL (MyISAM) has certain limitations that means it can