docs: security baseline — live USB boot checklist

Cross-reference from OSA audit (2026-06-23): SSH hardening,
MCP socket, firewall, listening ports, service accounts,
external MCP servers. Each check has command + expected output.

OSA exceptions documented: password auth kept for dev access.
USB should be stricter — key-only SSH, no 0.0.0.0 bindings.

Skill saved: security-audit-clawdie (freebsd category)

docs/SECURITY-BASELINE.md

@@ -0,0 +1,89 @@
+# Security Baseline — Live USB Boot Checklist
+
+2026-06-23 | OSA audit → live USB alignment
+
+Cross-reference of security checks that should pass on every booted
+Clawdie USB. Derived from the OSA security audit on 2026-06-23.
+
+## Boot-time checks
+
+### SSH hardening
+
+| Check | Command | Expected |
+|---|---|---|
+| Password auth disabled | `grep PasswordAuth /etc/ssh/sshd_config` | `PasswordAuthentication no` |
+| Root login disabled | `grep PermitRoot /etc/ssh/sshd_config` | `PermitRootLogin no` |
+| Key-only auth | `grep PubkeyAuth /etc/ssh/sshd_config` | `PubkeyAuthentication yes` |
+
+### Service accounts
+
+| Check | Command | Expected |
+|---|---|---|
+| colibri user exists | `pw usershow colibri` | uid 3002, shell `/usr/sbin/nologin` or `/bin/sh` with restrict |
+| colibri password locked | `pw usershow colibri \| grep '*'` | `*` (asterisk = locked) |
+| colibri in clawdie group | `id colibri` | includes `clawdie` group |
+| SSH key restricted | `cat /var/db/colibri/.ssh/authorized_keys` | `command="colibri-mcp-ssh",restrict,no-pty,...` |
+| Home dir owned by colibri | `ls -la /var/db/colibri/` | `colibri:colibri` on the directory itself |
+
+### MCP socket
+
+| Check | Command | Expected |
+|---|---|---|
+| Socket exists | `ls /var/run/colibri/colibri.sock` | exists |
+| Restricted to clawdie group | `ls -la /var/run/colibri/colibri.sock` | `srwxrwx--- clawdie:clawdie` |
+
+### Firewall (pf)
+
+| Check | Command | Expected |
+|---|---|---|
+| Default deny | `sudo pfctl -sr` | `block drop all` as final rule |
+| Only http/https public | `sudo pfctl -sr \| grep vtnet0` | only ports 80, 443 (and optionally 22) |
+| SSH Tailscale-only (optional) | `sudo pfctl -sr \| grep ssh` | no vtnet0 ssh rule, only tailscale0 |
+
+### Listening ports
+
+| Check | Command | Expected |
+|---|---|---|
+| No unexpected listeners | `sudo sockstat -l` | nginx (80/443), colibri (socket), sshd |
+| Dashboard Tailscale-only | `sudo sockstat -l \| grep 9119` | Hermes dashboard — should be on localhost or tailscale0 |
+| No 0.0.0.0 bindings | `sudo sockstat -l \| grep '*'` | only nginx 80/443 (public web), nothing else |
+
+### MCP access test
+
+| Check | Command | Expected |
+|---|---|---|
+| Local MCP works | `colibri-mcp tools` | lists tools |
+| SSH MCP from colibri user | `ssh -i mother-mcp colibri@localhost 'tools'` | lists tools (single-word invocation only) |
+| colibri_external_mcp_servers | via MCP tool | shows registered external servers |
+
+### External MCP servers
+
+| Check | Command | Expected |
+|---|---|---|
+| Config exists | `cat /usr/local/etc/colibri/external-mcp.json` | valid JSON with servers |
+| COLIBRI_MCP_EXTERNAL_CALL | `grep EXTERNAL_CALL /usr/local/etc/colibri/provider.env` | `COLIBRI_MCP_EXTERNAL_CALL=1` |
+| geodesic-dome-mcp installed | `ls /usr/local/bin/geodesic-dome-mcp` | exists, executable |
+| build-colibri.sh installed | `ls /usr/local/bin/build-colibri.sh` | exists, executable |
+| colibri-mcp-ssh wrapper | `ls /usr/local/bin/colibri-mcp-ssh` | exists, executable |
+
+## OSA-specific exceptions (production)
+
+| Exception | Reason |
+|---|---|
+| Password auth enabled on vtnet0 | User preference for OSA access during development |
+| SSH port 22 on public interface | OSA is the mother node, needs public SSH for now |
+| Port 9119 on 0.0.0.0 | Hermes dashboard, pf-limited to Tailscale on vtnet0 |
+
+These exceptions should NOT be present on a booted USB — the USB is a
+single-user operator station, not a public server.
+
+## Tests performed on OSA (2026-06-23)
+
+- ✅ SSH MCP from colibri user: `ssh -i mother-mcp colibri@localhost 'tools'` — works
+- ✅ Home dir ownership fixed: `chown colibri:colibri /var/db/colibri`
+- ✅ MCP socket permissions: `srwxrwx--- clawdie:clawdie`
+- ✅ pf firewall: default deny, only http/https/ssh on vtnet0
+- ✅ colibri authorized_keys: restrict + no-pty + forced command
+- ✅ COLIBRI_MCP_EXTERNAL_CALL=1 in provider.env
+- ✅ external-mcp.json: mother-build + geodesic-dome registered
+- ⚠️ Port 9119 (Hermes dashboard) bound to 0.0.0.0 — pf limits to Tailscale