chore: import upstream snapshot with attribution

scripts/lint.sh

@@ -0,0 +1,46 @@
+#!/usr/bin/env bash
+# lint.sh — Run all linters (clang-tidy + cppcheck + clang-format).
+#
+# Usage:
+#   scripts/lint.sh                                    # All 3 linters
+#   scripts/lint.sh CLANG_FORMAT=clang-format-20       # Override formatter
+#   scripts/lint.sh --ci                               # CI mode (skip clang-tidy)
+#
+# This script is the SINGLE source of truth for linting.
+
+set -euo pipefail
+
+ROOT="$(cd "$(dirname "$0")/.." && pwd)"
+cd "$ROOT"
+
+# shellcheck source=env.sh
+source "$ROOT/scripts/env.sh"
+
+# Check for --ci flag (skip clang-tidy for platforms without it)
+CI_ONLY=false
+MAKE_ARGS=()
+for arg in "$@"; do
+    if [ "$arg" = "--ci" ]; then
+        CI_ONLY=true
+    else
+        MAKE_ARGS+=("$arg")
+    fi
+done
+
+print_env "lint.sh"
+
+# No-skips policy: every test must pass or fail. The only tolerable skip is a
+# genuinely platform-specific test (SKIP_PLATFORM / #ifdef). Runs in both modes.
+echo "=== no-skips policy (tests pass or fail) ==="
+bash "$ROOT/scripts/check-no-test-skips.sh"
+
+if $CI_ONLY; then
+    echo "=== CI mode: cppcheck + clang-format ==="
+    make -j2 -f Makefile.cbm lint-ci "${MAKE_ARGS[@]+"${MAKE_ARGS[@]}"}"
+    echo "=== CI linters passed ==="
+else
+    echo "=== Full lint: clang-tidy + cppcheck + clang-format ==="
+    make -j3 -f Makefile.cbm lint "${MAKE_ARGS[@]+"${MAKE_ARGS[@]}"}"
+fi
+
+echo "=== All linters passed ==="