refactor: decouple Coin Hunter from Hermes for cross-platform usage

- Add unified coinhunter_shim.py that accepts subcommands (pre/gate/review/rotate-log)
- Update SKILL.md gate pseudocode to read optional ~/.coinhunter/platform.json
- Split cron/setup examples into Hermes and OpenClaw variants across docs
- Introduce platform.json schema in user-data-layout.md
- Remove stale auto_trader.py/run_trader.sh references from auto-trading-guide.md
- Keep legacy shims as backward-compatible wrappers

templates/rotate_external_gate_log_shim.py

@@ -0,0 +1,12 @@
+#!/usr/bin/env python3
+"""Hermes cron shim: runs coinhunter rotate-log via CLI."""
+import shutil
+import subprocess
+import sys
+
+BIN = shutil.which("coinhunter") or shutil.which("coinhunter.exe")
+if not BIN:
+    print("error: coinhunter CLI not found in PATH. Install with: pipx install coinhunter", file=sys.stderr)
+    sys.exit(127)
+
+sys.exit(subprocess.run([BIN, "rotate-log", *sys.argv[1:]]).returncode)