feat(runtime): add allocator reclaim controller status (#3406)

docs/architecture/background-services-inventory.md

@@ -49,7 +49,7 @@ not define a new scheduler, controller framework, or shutdown contract.
 | Dynamic config reload | Admin config handlers call `apply_dynamic_config_for_subsystem`, then `signal_dynamic_config_reload` or `signal_config_snapshot_reload` through the global notification system. | Applies scanner/heal runtime config, audit reloads, notification reloads, and peer reload signals. | Logs local and peer reload failures. Audit reload increments audit config reload metrics. | This is admin-triggered fanout, not a background scheduler. Controller work should preserve per-subsystem validation and error boundaries. |
 | Metrics runtime | `crates/obs/src/metrics/scheduler.rs::init_metrics_runtime` spawns multiple interval loops for cluster, bucket, node, resource, audit, notification, and replication bandwidth metrics. | Periodically collects and reports metrics. | Reports through the metrics runtime and logs cancellation warnings. | Keep intervals and collector grouping stable while adding status snapshots. |
 | Memory observability | `rustfs/src/memory_observability.rs::init_memory_observability` spawns a token-cancelled sampler. | Periodically records memory snapshots. | Emits memory observability metrics and exposes a read-only status snapshot plus a no-op reconcile plan for metrics enablement, interval, cancellation source, and shutdown handle shape. | This is the first low-risk pilot for controller status because it already has a simple token loop and the pilot does not mutate workers. |
-| Allocator reclaim | `rustfs/src/allocator_reclaim.rs::init_allocator_reclaim` spawns a token-cancelled reclaim loop when enabled. | Observes reclaimable work and may run allocator reclaim after idle intervals. | Emits reclaim enabled/backend counters, active-request gauges, scanner/heal activity gauges, and reclaim result counters. | A controller must preserve idle-streak logic and backend-specific force behavior. |
+| Allocator reclaim | `rustfs/src/allocator_reclaim.rs::init_allocator_reclaim` spawns a token-cancelled reclaim loop when enabled. | Observes reclaimable work and may run allocator reclaim after idle intervals. | Emits reclaim enabled/backend counters, active-request gauges, scanner/heal activity gauges, and reclaim result counters. Exposes a typed read-only status snapshot plus a no-op reconcile plan for enablement, backend, effective force, intervals, cancellation source, and shutdown handle shape. | A controller must preserve idle-streak logic and backend-specific force behavior. The current controller surface does not mutate workers. |
 | Auto-tuner | `rustfs/src/init.rs::init_auto_tuner` optionally spawns a 60-second loop when `RUSTFS_AUTOTUNER_ENABLED` is true. | Tunes concurrency manager settings from performance metrics. | Logs iteration success/failure. | Treat as behavior-sensitive; a future controller needs explicit rollback because it can change runtime concurrency. |
 | Update check | `rustfs/src/init.rs::init_update_check` spawns one async task with a 30-second timeout when update checks are enabled. | Performs version check network I/O and logs available updates. | Logs result only. | This is a one-shot task, not a controller candidate for the first BGC PRs. |
 | Deferred IAM recovery | `rustfs/src/startup_iam.rs::spawn_iam_recovery_task` retries IAM init with backoff and finalizes readiness when successful. | Can initialize IAM later, initialize AppContext if needed, mark `IamReady`, and publish `FullReady`. | Readiness state reflects deferred recovery progress. | Keep this lifecycle-critical path separate from generic background controllers. |