fix: fleet config issues from 2026-07-18 relay review

- hermes-agent-baseline: add gpu-dense and gpu-light to models list
- hermes-config-template: fix pgrep traps (exclude infisical wrapper) + add
  vault empty-key guard documentation in Rule 13
- litellm-api-keys: fix pgrep pattern in auditable check
- scripts/agent-health-check: fix pgrep to exclude infisical bash wrapper

Addresses issues found during relay inbox resolution session:
1. pgrep -f 'hermes_cli.main gateway run' matches both the real python
   gateway and the infisical bash wrapper, causing false health readings
2. infisical vault stores empty key silently — no guard/monitoring
3. gpu-dense/gpu-light stable aliases missing from baseline config

scripts/agent-health-check.py

@@ -184,8 +184,8 @@ def check_agents():
             print(f"  ⬜ {name} (CT {ct}): cannot SSH — skip liveness check")
             continue
 
-        # Gateway process
-        pid = ssh(host, "pgrep -f 'hermes_cli.main gateway run' | head -1", user=user)
+        # Gateway process (exclude the infisical bash wrapper that contains the same string)
+        pid = ssh(host, "pgrep -f 'hermes_cli.main gateway run' | grep -v infisical | head -1", user=user)
         if not pid:
             print(f"  ❌ {name}: GATEWAY NOT RUNNING")
             FAIL.append(f"gateway-down:{name}")