chore: add test runner to pre-commit hook with failure-only output

.husky/scripts/run-tests.sh

@@ -0,0 +1,24 @@
+#!/bin/sh
+# Run all tests and display only failing tests (plus a summary).
+# Keeps output focused so commit context isn't bloated.
+#
+# NOTE: It doesn't matter if you didn't introduce the failing tests —
+# they should be handled before committing. A red main branch helps no one.
+
+cd "$(dirname "$0")/../.."
+
+echo "🧪 Running tests (only failures will be shown)..."
+
+# Disable TTY progress bars for clean pre-commit output.
+# Use `--reporter=default` which prints only failures + the final summary.
+CI=true npx vitest run --reporter=default 2>&1
+EXIT_CODE=$?
+
+if [ $EXIT_CODE -ne 0 ]; then
+  echo ""
+  echo "⛔ Commit blocked: failing tests found."
+  echo "   It doesn't matter if you didn't introduce the failing tests —"
+  echo "   they should be handled before committing."
+fi
+
+exit $EXIT_CODE