Add command reference table and screen scrollback docs

- Table of all read and push commands with confirmed/not-tested/invalid status
- Note that save config caused a reboot on first run
- screen scrollback: Ctrl-A [ to enter copy mode, defscrollback in .screenrc

https://claude.ai/code/session_01JR2EMK7rwrZJowpstcaxQ6

README.md

@@ -670,6 +670,77 @@ docker compose ps
 
 ---
 
+## Command Reference — Tested Status
+
+Commands the script sends to the switch, with known test status. Use this as a guide when debugging unexpected behaviour — untested commands may behave differently on your firmware version.
+
+### Read commands
+
+| Command | Status | Notes |
+|---|---|---|
+| `show interfaces` | confirmed | |
+| `show poe-main-status` | confirmed | |
+| `show vlan` | confirmed | |
+| `show sys-info` | confirmed | |
+| `show arp` | confirmed | |
+| `show config` | confirmed | Returns table output |
+| `show ip helper-address` | not tested | |
+| `show ip route default` | not tested | |
+| `show dhcp-server leases` | invalid on this firmware | Script handles gracefully — returns empty |
+| `show dhcp-server static-binding` | invalid on this firmware | Script handles gracefully — returns empty |
+| `show dhcp-server` | invalid on this firmware | Script handles gracefully — returns empty |
+
+### Config / push commands
+
+| Command | Status | Notes |
+|---|---|---|
+| `enable` | confirmed | |
+| `configure terminal` | confirmed | |
+| `terminal length 0` | not tested | Disables pagination — sent before reads |
+| `interface FastEthernet {port}` | confirmed | |
+| `vlan members add {vid} {port}` | confirmed | |
+| `vlan pvid {port} {vid}` | not tested | Sets native/untagged VLAN on a port |
+| `vlan tagging {tagged-set} {port}` | not tested | Adds trunk tagging |
+| `vlan create {vid} name "x" type port` | not tested | |
+| `no vlan {vid}` | not tested | |
+| `name "{description}"` (under interface) | not tested | Sets port description |
+| `shutdown` (under interface) | not tested | Disables a port |
+| `poe enable` / `no poe enable` | not tested | |
+| `poe poe-limit {milliwatts}` | not tested | |
+| `interface vlan {vid}` (in config mode) | not tested | |
+| `ip access-list extended {name}` | not tested | |
+| `ip access-group {name} in/out` | not tested | |
+| `end` | not tested | Returns to enable mode |
+| `save config` | confirmed | **Caused a reboot on first run** — watch the first time you push this |
+
+> **`save config` reboot note:** On at least one switch, issuing `save config` triggered a reboot. This may be firmware-version-specific or a one-time behaviour after certain config states. Subsequent saves have not reproduced it. Be aware when pushing config changes in a live environment.
+
+---
+
+## Scrollback in `screen` (console cable sessions)
+
+By default `screen` does not let you scroll up through output. Enable it with copy mode:
+
+| Action | Keys |
+|---|---|
+| Enter scrollback mode | `Ctrl-A` then `[` |
+| Scroll up / down | Arrow keys or `PgUp` / `PgDn` |
+| Exit scrollback mode | `Esc` or `q` |
+
+To increase the scrollback buffer for a session (default is only 100 lines):
+```
+Ctrl-A  then  :scrollback 5000
+```
+
+To set it permanently, add this to `~/.screenrc`:
+```
+defscrollback 5000
+```
+
+Useful when reviewing long `show config` or `show interfaces` output during console sessions.
+
+---
+
 ## What This Tool Does Not Do
 
 - Does not manage OPNsense, pfSense, or any other device directly (OPNsense integration is read/sync only)