feat(api): idle container reaper (MS22-P1k) (#614)

Co-authored-by: Jason Woltje <jason@diversecanvas.com>
Co-committed-by: Jason Woltje <jason@diversecanvas.com>

apps/api/src/container-reaper/container-reaper.service.ts

@@ -0,0 +1,30 @@
+import { Injectable, Logger } from "@nestjs/common";
+import { Cron, CronExpression } from "@nestjs/schedule";
+import { ContainerLifecycleService } from "../container-lifecycle/container-lifecycle.service";
+
+@Injectable()
+export class ContainerReaperService {
+  private readonly logger = new Logger(ContainerReaperService.name);
+
+  constructor(private readonly containerLifecycle: ContainerLifecycleService) {}
+
+  @Cron(CronExpression.EVERY_5_MINUTES)
+  async reapIdleContainers(): Promise<void> {
+    this.logger.log("Running idle container reap cycle...");
+    try {
+      const result = await this.containerLifecycle.reapIdle();
+      if (result.stopped.length > 0) {
+        this.logger.log(
+          `Stopped ${String(result.stopped.length)} idle containers: ${result.stopped.join(", ")}`
+        );
+      } else {
+        this.logger.debug("No idle containers to stop");
+      }
+    } catch (error) {
+      this.logger.error(
+        "Failed to reap idle containers",
+        error instanceof Error ? error.stack : String(error)
+      );
+    }
+  }
+}