security: harden secret hygiene and pre-commit scanning

scripts/check-secrets.sh

@@ -0,0 +1,56 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+if ! git rev-parse --git-dir >/dev/null 2>&1; then
+  echo "Not inside a git repository."
+  exit 1
+fi
+
+if ! command -v rg >/dev/null 2>&1; then
+  echo "ripgrep (rg) is required for secret scanning."
+  exit 1
+fi
+
+staged_files=()
+while IFS= read -r file; do
+  staged_files+=("$file")
+done < <(git diff --cached --name-only --diff-filter=ACMRTUXB)
+
+if [ "${#staged_files[@]}" -eq 0 ]; then
+  exit 0
+fi
+
+secret_pattern='AKIA[0-9A-Z]{16}|ASIA[0-9A-Z]{16}|ghp_[A-Za-z0-9]{36}|github_pat_[A-Za-z0-9_]{20,}|xox[baprs]-[A-Za-z0-9-]{10,}|AIza[0-9A-Za-z_-]{35}|-----BEGIN (RSA|OPENSSH|EC|DSA|PRIVATE) KEY-----|(?i)(password|passwd|pwd|secret|token|api[_-]?key|jwt_secret)\s*[:=]\s*["'"'"'][^"'"'"'\s]{8,}["'"'"']'
+allow_pattern='CHANGE_ME|REDACTED|PLACEHOLDER|EXAMPLE|example|<[^>]+>'
+
+found=0
+
+for file in "${staged_files[@]}"; do
+  case "$file" in
+    dist/*|*.png|*.jpg|*.jpeg|*.gif|*.webp|*.pdf|*.zip|*.gz|*.exe|*.dll|*.so|*.dylib)
+      continue
+      ;;
+  esac
+
+  if ! content="$(git show ":$file" 2>/dev/null)"; then
+    continue
+  fi
+
+  hits="$(printf '%s' "$content" | rg -n --no-heading -e "$secret_pattern" || true)"
+  if [ -n "$hits" ]; then
+    filtered="$(printf '%s\n' "$hits" | rg -v -e "$allow_pattern" || true)"
+    if [ -n "$filtered" ]; then
+      echo "Potential secret found in staged file: $file"
+      printf '%s\n' "$filtered"
+      found=1
+    fi
+  fi
+done
+
+if [ "$found" -ne 0 ]; then
+  echo
+  echo "Commit blocked: remove or redact secrets before committing."
+  exit 1
+fi
+
+exit 0