SCRAPE-12: Implement in-process mutex (isScraperRunning flag) (#17)

Co-authored-by: Stephen Minakian <stephenminakian@gmail.com>
Co-committed-by: Stephen Minakian <stephenminakian@gmail.com>

jobs/scraperJob.js

@@ -0,0 +1,48 @@
+// In-process mutex state
+let isRunning = false;
+let currentJobId = null;
+
+/**
+ * Check if scraper is currently running
+ * @returns {boolean}
+ */
+function isScraperRunning() {
+  return isRunning;
+}
+
+/**
+ * Get current job ID if running
+ * @returns {string|null}
+ */
+function getCurrentJobId() {
+  return currentJobId;
+}
+
+/**
+ * Acquire the scraper lock
+ * @param {string} jobId - Job ID to set
+ * @returns {boolean} True if lock acquired
+ */
+function acquireLock(jobId) {
+  if (isRunning) {
+    return false;
+  }
+  isRunning = true;
+  currentJobId = jobId;
+  return true;
+}
+
+/**
+ * Release the scraper lock
+ */
+function releaseLock() {
+  isRunning = false;
+  currentJobId = null;
+}
+
+module.exports = {
+  isScraperRunning,
+  getCurrentJobId,
+  acquireLock,
+  releaseLock
+};