Add S3 backend and storage verification

workplans/ARTIFACT-STORE-WP-0004-s3-compatible-backend.md

@@ -4,13 +4,13 @@ type: workplan
 title: "S3-Compatible Backend (Ceph RGW Target)"
 repo: artifact-store
 domain: stack
-status: planned
+status: active
 owner: codex
 topic_slug: stack
 planning_priority: medium
 planning_order: 4
 created: "2026-05-15"
-updated: "2026-05-15"
+updated: "2026-05-16"
 state_hub_workstream_id: "d0526cfc-e532-431f-970d-f3e548d27a80"
 ---
 
@@ -38,9 +38,9 @@ registry.
 
 ```task
 id: ARTIFACT-STORE-WP-0004-T001
-status: cancelled
+status: done
 priority: high
-state_hub_task_id: "7b980a55-2364-48c3-98ac-081629a8d2b7"
+state_hub_task_id: "1db0d548-cdac-4b07-962b-bcafa3aae30e"
 ```
 
 Acceptance:
@@ -58,7 +58,7 @@ Acceptance:
 
 ```task
 id: ARTIFACT-STORE-WP-0004-T002
-status: todo
+status: done
 priority: high
 state_hub_task_id: "14b50595-5820-4369-b037-b015fcbddcc4"
 ```
@@ -75,11 +75,15 @@ Acceptance:
 - `head`, `delete`, `health` implemented.
 - `delete` is idempotent (delete-of-missing returns success).
 
+Decision: use `aioboto3` as the optional S3 client dependency. The
+backend imports it lazily so local-only deployments do not need S3
+dependencies installed.
+
 ## D4.3 - Backend Selection And Routing
 
 ```task
 id: ARTIFACT-STORE-WP-0004-T003
-status: todo
+status: done
 priority: medium
 state_hub_task_id: "725dafd6-3337-4f81-b221-bb9f3a564d7e"
 ```
@@ -97,7 +101,7 @@ Acceptance:
 
 ```task
 id: ARTIFACT-STORE-WP-0004-T004
-status: todo
+status: blocked
 priority: high
 state_hub_task_id: "4fd7b73b-7058-4edd-b5e3-edca396760d4"
 ```
@@ -111,11 +115,15 @@ Acceptance:
   endpoint; results recorded in `docs/OPERATOR.md`.
 - No CI dependency on a live Ceph or AWS account.
 
+Blocked note: Docker is available, but this environment does not have
+`aioboto3`, `boto3`, `testcontainers`, `uv`, or `pip`; MinIO container
+tests need dependency/bootstrap support before they can be run honestly.
+
 ## D4.5 - Verification Pass
 
 ```task
 id: ARTIFACT-STORE-WP-0004-T005
-status: todo
+status: done
 priority: medium
 state_hub_task_id: "5a55546f-288f-4da0-a646-3d9319908279"
 ```