Preserve per-source pacing across queue jobs and add source pause

scraper/lib/http.js

@@ -3,10 +3,24 @@
 const { PoliteGate, sleep } = require('./delay');
 
 class StopScrapeError extends Error {}
+const sourceGates = new Map();
+
+function gateFor(options) {
+  const next = new PoliteGate(options);
+  if (!options.gateKey) return next;
+  const key = String(options.gateKey);
+  const existing = sourceGates.get(key);
+  if (!existing) { sourceGates.set(key, next); return next; }
+  // A new job may use updated host settings, but it must not forget when the
+  // previous job last requested this same source.
+  existing.minMs = next.minMs;
+  existing.maxMs = next.maxMs;
+  return existing;
+}
 
 class SlowHttp {
   constructor(options = {}) {
-    this.gate = new PoliteGate(options);
+    this.gate = gateFor(options);
     this.userAgent = options.userAgent || 'MangaCircus-Scraper/1.0 (personal archival; sequential requests)';
     this.maxRetries = options.maxRetries ?? 2;
     this.onEvent = options.onEvent;