fix(lifecycle): clean up service subscriptions, proxy retries, and stale runtime state on shutdown

ts/classes.cert-provision-scheduler.ts

@@ -61,14 +61,21 @@ export class CertProvisionScheduler {
   }
 
   /**
-   * Check if a domain is currently in backoff
+   * Check if a domain is currently in backoff.
+   * Expired entries are pruned from the cache to prevent unbounded growth.
    */
   async isInBackoff(domain: string): Promise<boolean> {
     const entry = await this.loadBackoff(domain);
     if (!entry) return false;
 
     const retryAfter = new Date(entry.retryAfter);
-    return retryAfter.getTime() > Date.now();
+    if (retryAfter.getTime() > Date.now()) {
+      return true;
+    }
+
+    // Backoff has expired — prune the stale entry
+    this.backoffCache.delete(domain);
+    return false;
   }
 
   /**
@@ -124,9 +131,12 @@ export class CertProvisionScheduler {
     const entry = await this.loadBackoff(domain);
     if (!entry) return null;
 
-    // Only return if still in backoff
+    // Only return if still in backoff — prune expired entries
     const retryAfter = new Date(entry.retryAfter);
-    if (retryAfter.getTime() <= Date.now()) return null;
+    if (retryAfter.getTime() <= Date.now()) {
+      this.backoffCache.delete(domain);
+      return null;
+    }
 
     return {
       failures: entry.failures,