Add Slurp'it network discovery setup and agent service accounts

- Enable SNMP on MikroTik router
- Configure SNMP v2c credentials (public, netdisco)
- Create agent service account on Unraid, router, AP
- Document network discovery stack (Slurp'it, NetDisco, NetBox)
- Update changelog with configuration changes

docs/06-CHANGELOG.md

@@ -1,3 +1,28 @@
+## 2026-01-22 - Slurp'it Network Discovery Setup
+
+### SNMP Configuration
+- [MIKROTIK] Enabled SNMP on router (192.168.31.1)
+- [SNMP] Communities configured: public, netdisco
+- [DISCOVERY] MikroTik router discovered via SNMP
+
+### Agent Service Account
+- [UNRAID] Created agent user with SSH key access (port 422)
+- [MIKROTIK-ROUTER] Created agent user with SSH key (port 2222)
+- [MIKROTIK-AP] Created agent user with password auth (port 2222)
+- [SWITCH] CSS326 uses SwOS - no SSH support
+
+### Slurp'it Configuration
+- [SNMP] Added SNMP v2c credentials to vault (public, netdisco)
+- [NETBOX] Enabled NetBox integration plugin
+- [SCAN] Configured scan target: 192.168.31.0/24
+
+### Documentation
+- [DOCS] Added Network Discovery section to 00-CURRENT-STATE.md
+- [DOCS] Created AGENT-CREDENTIALS.md (gitignored)
+- [DIAGRAM] Added INFRASTRUCTURE-DIAGRAM.md with complete topology
+
+---
+
 ## 2026-01-22 - MikroTik DNS Migration to AdGuard Home
 
 ### Pi-hole Removal from MikroTik