feat: initial companion repo for CC-024 Hooks

hooks/post-tool-use.sh

@@ -0,0 +1,51 @@
+#!/bin/bash
+# post-tool-use.sh: Append an audit log entry after every tool call.
+#
+# Claude Code calls this script AFTER every tool execution.
+# The script receives a JSON object on stdin with two fields:
+#   - tool_name: the name of the tool that ran (e.g., "Bash", "Read", "Write")
+#   - tool_input: the arguments passed to the tool
+#
+# This script writes one line to hooks/audit.log:
+#   2026-03-30T04:12:33Z | Bash | ls -la /tmp
+#
+# The log is append-only. It grows during the session and persists between sessions.
+# Read it any time with: cat hooks/audit.log
+#
+# Exit code:
+#   0  Always. This hook does not block anything.
+#
+# Make this script executable: chmod +x hooks/post-tool-use.sh
+
+# Read the full JSON payload from stdin
+input=$(cat)
+
+# Extract the tool name
+tool_name=$(echo "$input" | python3 -c "import sys,json; print(json.load(sys.stdin).get('tool_name','unknown'))" 2>/dev/null || echo "unknown")
+
+# Extract the most relevant part of the tool input.
+# Different tools use different argument keys:
+#   Bash   -> command
+#   Read   -> file_path
+#   Write  -> file_path
+#   Grep   -> pattern
+# Fall back to a truncated string representation of the entire input dict.
+tool_input=$(echo "$input" | python3 -c "
+import sys, json
+d = json.load(sys.stdin).get('tool_input', {})
+value = d.get('command') or d.get('file_path') or d.get('pattern') or str(d)[:120]
+print(value)
+" 2>/dev/null || echo "(parse error)")
+
+# Timestamp in UTC ISO 8601
+timestamp=$(date -u +"%Y-%m-%dT%H:%M:%SZ")
+
+# Write the log directory relative to this script's location.
+# This keeps the log inside the repo regardless of where Claude Code is invoked from.
+log_dir="$(dirname "$0")"
+log_file="$log_dir/audit.log"
+
+# Append one line to the log file
+echo "$timestamp | $tool_name | $tool_input" >> "$log_file"
+
+exit 0