feat(templates): add governance and approval gate templates (Paperclip pattern)

Session 4 step 17 — 5 autonomy levels (0-4), PreToolUse approval-gate
hook polls approval-responses.jsonl with 60s timeout, blocks on no-response.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

scripts/templates/governance/approval-gate.sh

@@ -0,0 +1,162 @@
+#!/bin/bash
+# PreToolUse hook: Implement approval gates based on GOVERNANCE.md.
+# Bash 3.2 compatible. Uses python3 for JSON/MD parsing.
+#
+# Follows Paperclip's approval mechanism:
+# 1. Read GOVERNANCE.md for current autonomy level and gate definitions
+# 2. Auto-approve or require human approval based on level
+# 3. Write pending approval requests; check for responses
+# 4. Timeout with no response → block
+#
+# Placeholders:
+#   {{WORKING_DIR}} - absolute path to project directory
+
+WORKING_DIR="{{WORKING_DIR}}"
+GOVERNANCE_DIR="$WORKING_DIR/governance"
+GOVERNANCE_FILE="$WORKING_DIR/GOVERNANCE.md"
+PENDING_FILE="$GOVERNANCE_DIR/pending-approvals.jsonl"
+RESPONSES_FILE="$GOVERNANCE_DIR/approval-responses.jsonl"
+AUDIT_LOG="$GOVERNANCE_DIR/audit.log"
+APPROVALS_LOG="$GOVERNANCE_DIR/approvals.log"
+APPROVAL_TIMEOUT=60
+
+mkdir -p "$GOVERNANCE_DIR"
+
+# Read hook input
+INPUT=$(cat)
+
+# Auto-approve tools based on autonomy level
+DECISION=$(GOVERNANCE_FILE="$GOVERNANCE_FILE" python3 -c "
+import re, json, sys, os
+
+governance_file = os.environ.get('GOVERNANCE_FILE', '')
+
+try:
+    data = json.loads('''$INPUT''')
+except:
+    print('approve')
+    sys.exit(0)
+
+tool_name = data.get('tool_name', '')
+
+# Read governance policy
+if not os.path.exists(governance_file):
+    print('approve')
+    sys.exit(0)
+
+content = open(governance_file).read()
+level_m = re.search(r'Current level:\s*(\d+)', content)
+level = int(level_m.group(1)) if level_m else 0
+
+# Safe read-only tools (always approved at level 1+)
+read_tools = ['Read', 'Glob', 'Grep', 'LS']
+# File operation tools (approved at level 2+)
+file_tools = ['Write', 'Edit', 'MultiEdit']
+# Non-destructive bash (approved at level 3+)
+# Level 4: everything auto-approved
+
+if level >= 4:
+    print('approve')
+elif level >= 3 and tool_name not in ['Bash']:
+    print('approve')
+elif level >= 2 and tool_name in read_tools + file_tools:
+    print('approve')
+elif level >= 1 and tool_name in read_tools:
+    print('approve')
+else:
+    print('gate')
+" 2>/dev/null)
+
+# Log every tool call to audit log
+python3 -c "
+import json, time, os
+try:
+    data = json.loads('''$INPUT''')
+    tool_name = data.get('tool_name', 'unknown')
+    entry = time.strftime('%Y-%m-%dT%H:%M:%SZ', time.gmtime()) + ' TOOL ' + tool_name + ' decision=$DECISION'
+    with open('$AUDIT_LOG', 'a') as f:
+        f.write(entry + '\n')
+except:
+    pass
+" 2>/dev/null
+
+if [ "$DECISION" = "approve" ]; then
+  exit 0
+fi
+
+# Gate: write pending approval request
+REQUEST_ID=$(python3 -c "import time; print(str(int(time.time())))" 2>/dev/null)
+python3 -c "
+import json, time, os
+try:
+    data = json.loads('''$INPUT''')
+    tool_name = data.get('tool_name', 'unknown')
+    tool_input = data.get('tool_input', {})
+    req = {
+        'id': '$REQUEST_ID',
+        'timestamp': time.strftime('%Y-%m-%dT%H:%M:%SZ', time.gmtime()),
+        'tool_name': tool_name,
+        'tool_input_summary': str(tool_input)[:200],
+        'status': 'pending'
+    }
+    with open('$PENDING_FILE', 'a') as f:
+        f.write(json.dumps(req) + '\n')
+    print('Approval required for: ' + tool_name)
+    print('Request ID: $REQUEST_ID')
+    print('Add response to: $RESPONSES_FILE')
+    print('Format: {\"id\": \"$REQUEST_ID\", \"decision\": \"approve\"}')
+except:
+    pass
+" >&2
+
+# Poll for response
+SECONDS_WAITED=0
+while [ "$SECONDS_WAITED" -lt "$APPROVAL_TIMEOUT" ]; do
+  if [ -f "$RESPONSES_FILE" ]; then
+    RESPONSE=$(python3 -c "
+import json, os
+req_id = '$REQUEST_ID'
+responses_file = '$RESPONSES_FILE'
+try:
+    with open(responses_file) as f:
+        for line in f:
+            line = line.strip()
+            if line:
+                try:
+                    r = json.loads(line)
+                    if r.get('id') == req_id:
+                        print(r.get('decision', 'deny'))
+                        exit(0)
+                except:
+                    pass
+except:
+    pass
+print('pending')
+" 2>/dev/null)
+    if [ "$RESPONSE" = "approve" ]; then
+      python3 -c "
+import json, time
+entry = {'id': '$REQUEST_ID', 'timestamp': '$(date -u +%Y-%m-%dT%H:%M:%SZ)', 'decision': 'approved'}
+with open('$APPROVALS_LOG', 'a') as f:
+    f.write(json.dumps(entry) + '\n')
+" 2>/dev/null
+      exit 0
+    elif [ "$RESPONSE" = "deny" ]; then
+      python3 -c "
+import json, time
+entry = {'id': '$REQUEST_ID', 'timestamp': '$(date -u +%Y-%m-%dT%H:%M:%SZ)', 'decision': 'denied'}
+with open('$APPROVALS_LOG', 'a') as f:
+    f.write(json.dumps(entry) + '\n')
+" 2>/dev/null
+      echo '{"decision": "block", "reason": "Approval denied by operator."}'
+      exit 2
+    fi
+  fi
+  sleep 5
+  SECONDS_WAITED=$(( SECONDS_WAITED + 5 ))
+done
+
+# Timeout — block
+echo "Approval timeout after ${APPROVAL_TIMEOUT}s — blocking tool call." >&2
+echo '{"decision": "block", "reason": "Approval timeout. Check governance/pending-approvals.jsonl."}'
+exit 2