fix(hermes): wire all three contracts to reachability helper

The helper was correct but dead code - nothing called it. This commit:
1. Makes the helper runnable standalone: scripts/hermes-reachability-check.sh <host> <pattern> <path>
2. Wires all THREE contracts to it:
   - hermes-key-enforcement.prose.md
   - hermes-config-template.prose.md
   - hermes-agent-baseline.prose.md
3. Each contract now explicitly instructs to run the helper and interpret the three outcomes
4. States that the bug this replaces was deriving reachability from the remote grep's exit code

Files changed (4):
- scripts/hermes-reachability-check.sh (standalone mode added)
- hermes-key-enforcement.prose.md (reachability section added)
- hermes-config-template.prose.md (reachability section added)
- hermes-agent-baseline.prose.md (reachability section added)

hermes-agent-baseline.prose.md

@@ -11,6 +11,24 @@ author: Abiba (pi agent)
 
 # Hermes Agent Baseline — Canonical Good State
 
+## Reachability Detection
+
+Before checking agent baseline, verify the host is reachable and can be audited. Use the shared reachability helper from the clone root:
+
+```bash
+# Run on each host to check reachability (Tanko, Mumuni, Koonimo, Koby)
+scripts/hermes-reachability-check.sh <host> "api_key:" "/root/.hermes/config.yaml"
+# Example: scripts/hermes-reachability-check.sh 192.168.68.122 "api_key:" "/root/.hermes/config.yaml"
+
+# Expected outcomes:
+# - UNREACHABLE: SSH connection failed (host is down)
+# - VIOLATION: SSH succeeded and found matches (report the finding)
+# - COMPLIANT: SSH succeeded and found no matches (no api_key in config)
+#
+# NOTE: The bug this replaces was deriving reachability from the remote grep's exit code.
+# The correct pattern: remote side always succeeds (grep ...; true), so ssh status = connection only.
+```
+
 ## Quick Restore
 
 ```bash

hermes-config-template.prose.md

@@ -19,6 +19,24 @@ description: >
 - agent_keys: map (see Agent Keys section)
 - infra_endpoints_verified: array
 
+## Reachability Detection
+
+Before auditing the config template, verify the host is reachable and can be checked. Use the shared reachability helper from the clone root:
+
+```bash
+# Run on each host to check reachability (Tanko, Mumuni, Koonimo, Koby)
+scripts/hermes-reachability-check.sh <host> "base_url:" "/root/.hermes/config.yaml"
+# Example: scripts/hermes-reachability-check.sh 192.168.68.122 "base_url:" "/root/.hermes/config.yaml"
+
+# Expected outcomes:
+# - UNREACHABLE: SSH connection failed (host is down)
+# - VIOLATION: SSH succeeded and found matches (report the finding)
+# - COMPLIANT: SSH succeeded and found no matches (no base_url in config)
+#
+# NOTE: The bug this replaces was deriving reachability from the remote grep's exit code.
+# The correct pattern: remote side always succeeds (grep ...; true), so ssh status = connection only.
+```
+
 ## Agent Keys (LiteLLM — Current 2026-07-11)
 
 Each agent has a unique LiteLLM API key (virtual key) generated against the LiteLLM

hermes-key-enforcement.prose.md

@@ -117,6 +117,24 @@ model:
   api_key_env: LITELLM_API_KEY
 ```
 
+## Reachability Detection
+
+Before checking for hardcoded keys, verify the host is reachable and can be audited. Use the shared reachability helper from the clone root:
+
+```bash
+# Run on each host to check reachability (Tanko, Mumuni, Koonimo, Koby)
+scripts/hermes-reachability-check.sh <host> "api_key: sk-" "/root/.hermes/"
+# Example: scripts/hermes-reachability-check.sh 192.168.68.122 "api_key: sk-" "/root/.hermes/"
+
+# Expected outcomes:
+# - UNREACHABLE: SSH connection failed (host is down)
+# - VIOLATION: SSH succeeded and found matches (report the finding)
+# - COMPLIANT: SSH succeeded and found no matches (no hardcoded keys in config)
+#
+# NOTE: The bug this replaces was deriving reachability from the remote grep's exit code.
+# The correct pattern: remote side always succeeds (grep ...; true), so ssh status = connection only.
+```
+
 ## Detection Query
 
 Run on any Hermes host to detect violations:

scripts/hermes-reachability-check.sh

@@ -0,0 +1,32 @@
+#!/bin/bash
+# Shared helper for Hermes contract reachability checks
+# Separates SSH exit status from remote command result
+
+hermes_check_host() {
+    local host=$1
+    local pattern=$2
+    local path=$3
+    
+    # Remote side always succeeds (grep ...; true), so ssh exit code = connection status only
+    local out
+    out=$(ssh -o BatchMode=yes -o ConnectTimeout=3 root@"$host" "grep -RIn '$pattern' '$path' 2>/dev/null; true" 2>/dev/null)
+    local status=$?
+    
+    if [ $status -ne 0 ]; then
+        echo "$host: UNREACHABLE (ssh exit $status)"
+    elif [ -n "$out" ]; then
+        echo "$host: VIOLATION: $out"
+    else
+        echo "$host: COMPLIANT (no matches found)"
+    fi
+}
+
+# Standalone mode: scripts/hermes-reachability-check.sh <host> <pattern> <path>
+if [ "${BASH_SOURCE[0]}" = "${0}" ]; then
+    if [ $# -ne 3 ]; then
+        echo "Usage: $0 <host> <pattern> <path>" >&2
+        exit 2
+    fi
+    hermes_check_host "$1" "$2" "$3"
+    exit 0
+fi