Add pre-commit hook enforcing 30s test suite time limit (#132)

scripts/pre-commit-hook.sh

@@ -0,0 +1,22 @@
+#!/usr/bin/env bash
+# Pre-commit hook: run tests with a wall-clock limit.
+# Blocks the commit if tests fail or take too long.
+# Current baseline: ~18s wall-clock. Limit set to 30s for headroom.
+
+MAX_SECONDS=30
+
+echo "Running tests (${MAX_SECONDS}s limit)..."
+
+timeout "${MAX_SECONDS}" poetry run pytest tests -q --tb=short --timeout=10
+exit_code=$?
+
+if [ "$exit_code" -eq 124 ]; then
+    echo ""
+    echo "BLOCKED: tests exceeded ${MAX_SECONDS}s wall-clock limit."
+    echo "Speed up slow tests before committing."
+    exit 1
+elif [ "$exit_code" -ne 0 ]; then
+    echo ""
+    echo "BLOCKED: tests failed."
+    exit 1
+fi