feat: enhance storage stats and cluster health reporting

- Introduced new data structures for bucket and storage statistics, including BucketSummary, StorageStats, and ClusterHealth.
- Implemented runtime statistics tracking for buckets, including object count and total size.
- Added methods to retrieve storage stats and bucket summaries in the FileStore.
- Enhanced the SmartStorage interface to expose storage stats and cluster health.
- Implemented tests for runtime stats, cluster health, and credential management.
- Added support for runtime-managed credentials with atomic replacement.
- Improved filesystem usage reporting for storage locations.

readme.hints.md

@@ -11,6 +11,9 @@
 - **Bucket policies** (AWS/MinIO-compatible JSON policies, public access support)
 - CORS support
 - ListBuckets, ListObjects (v1/v2), CopyObject
+- Runtime bucket summaries and storage stats via the Rust bridge (no S3 list scans)
+- Cluster health introspection via the Rust bridge (node membership, local drive probes, quorum, healing state)
+- Runtime credential listing and atomic replacement via the Rust bridge
 
 ## Architecture
 
@@ -20,6 +23,7 @@
 - `management.rs` - IPC loop (newline-delimited JSON over stdin/stdout)
 - `server.rs` - hyper 1.x HTTP server, routing, CORS, auth+policy pipeline, all S3-compatible handlers
 - `storage.rs` - FileStore: filesystem-backed storage, multipart manager, `.policies/` dir
+- `storage.rs` also owns the runtime stats cache and standalone storage scans used by the bridge stats API
 - `xml_response.rs` - S3-compatible XML response builders
 - `error.rs` - StorageError codes with HTTP status mapping
 - `auth.rs` - AWS SigV4 signature verification (HMAC-SHA256, clock skew, constant-time compare)
@@ -37,6 +41,11 @@
 | `start` | `{ config: ISmartStorageConfig }` | Init storage + HTTP server |
 | `stop` | `{}` | Graceful shutdown |
 | `createBucket` | `{ name: string }` | Create bucket directory |
+| `getStorageStats` | `{}` | Return cached bucket/global runtime stats + storage location capacity snapshots |
+| `listBucketSummaries` | `{}` | Return cached per-bucket runtime summaries |
+| `listCredentials` | `{}` | Return the active runtime auth credential set |
+| `replaceCredentials` | `{ credentials: IStorageCredential[] }` | Atomically replace the runtime auth credential set |
+| `getClusterHealth` | `{}` | Return runtime cluster health or `{ enabled: false }` in standalone mode |
 
 ### Storage Layout
 - Objects: `{root}/{bucket}/{key}._storage_object`
@@ -60,7 +69,10 @@
 
 ## Testing
 
-- `test/test.aws-sdk.node.ts` - AWS SDK v3 compatibility (10 tests, auth disabled, port 3337)
+- `test/test.aws-sdk.node.ts` - AWS SDK v3 compatibility + runtime stats coverage (18 tests, auth disabled, port 3337)
+- `test/test.aws-sdk.node.ts` - AWS SDK v3 compatibility + runtime stats + standalone cluster health coverage (19 tests, auth disabled, port 3337)
+- `test/test.credentials.node.ts` - runtime credential rotation coverage (10 tests, auth enabled, port 3349)
+- `test/test.cluster-health.node.ts` - single-node cluster health coverage (4 tests, S3 port 3348, QUIC port 4348)
 - `test/test.auth.node.ts` - Auth + bucket policy integration (20 tests, auth enabled, port 3344)
 - `test/test.policy-crud.node.ts` - Policy API CRUD + validation edge cases (17 tests, port 3345)
 - `test/test.policy-eval.node.ts` - Policy evaluation: principals, actions, resources, deny-vs-allow (22 tests, port 3346)