The backend S3 client now resolves credentials from user-configurable environment variables

README.md

@@ -71,7 +71,7 @@ Narratio now includes configuration and path-model foundations for archive suppo
 
 Implemented foundations:
 
-- `pipeline.storage.s3` config shape (`bucket`, `root_prefix`, `region`, `endpoint`, `force_path_style`)
+- `pipeline.storage.s3` config shape (`bucket`, `root_prefix`, `region`, `endpoint`, `force_path_style`, `access_key_id_env`, `secret_access_key_env`)
 - `pipeline.spool` config shape (`root`, `delete_audio_after_archive`)
 - `pipeline.archive` config shape (`enabled`, `upload_run`, `promote_artifacts`)
 - promotion-rule validation (`from`/`to` required, relative-only paths, traversal rejected)
@@ -83,6 +83,8 @@ Implemented foundations:
 Current defaults:
 
 - `pipeline.storage.s3.root_prefix`: `dnd`
+- `pipeline.storage.s3.access_key_id_env`: `OBJECT_STORAGE_KEY_ID`
+- `pipeline.storage.s3.secret_access_key_env`: `OBJECT_STORAGE_KEY`
 - `pipeline.workspace.cleanup_after_archive`: `false`
 - `pipeline.spool.root`: `/var/spool/narratio`
 - `pipeline.spool.delete_audio_after_archive`: `false`
@@ -110,7 +112,8 @@ Current boundaries:
   - `pipeline.workspace.cleanup_after_archive: true` removes only the run-scoped local workdir after successful archive commit
   - cleanup executes only after all selected stages for the command invocation succeed
   - cleanup does not run for failed, incomplete, skipped, or unarchived runs
-  - local development `audio_dir`/`audio_files` source inputs are never deleted by spool cleanup
+- local development `audio_dir`/`audio_files` source inputs are never deleted by spool cleanup
+- S3 credentials are resolved from configured env-var names when both are present; if either is missing, Narratio falls back to the AWS SDK default credential chain
 
 S3 input details and current boundaries are documented in [docs/s3-audio-input.md](docs/s3-audio-input.md).