Mlflow implementation (#2)

Reviewed-on: #2

README.md

@@ -78,9 +78,13 @@ To provision an MLflow tracking server, set:
 ```yaml
 mlflow:
   mode: create
-  tracking_server_name: your-tracking-server-name
+  experiment_name: qc-cli-training
+  registered_model_name: qc-cli-model
+  register_trained_models: true
 ```
 
+In `create` mode, the CLI manages the tracking server name from `infra.stack_name`; you do not need to set `tracking_server_name`.
+
 To use an existing MLflow tracking server, set:
 
 ```yaml
@@ -89,6 +93,16 @@ mlflow:
   tracking_server_name: your-tracking-server-name
 ```
 
+When MLflow is enabled, `train start` creates an MLflow run for the SageMaker job. `train status` finalizes that run once the job reaches a terminal state and registers completed model artifacts as experiment model versions using the `experiment-latest` MLflow alias. An experiment version is an immutable trained-source artifact; it records that training produced a model, not that the model is better than earlier versions or ready for release.
+
+To open the managed SageMaker MLflow UI, request a fresh presigned URL:
+
+```bash
+qc-cli infra mlflow-url --config config.yaml
+```
+
+This works for `mode: create` and for `mode: existing` when the existing server is managed by Amazon SageMaker. In `create` mode, the command uses the CLI-managed tracking server name. In `existing` mode, it uses `mlflow.tracking_server_name`. If the existing MLflow server is external to SageMaker, open it with that server's own URL instead.
+
 ## Commands
 
 ### `init`
@@ -106,6 +120,7 @@ qc-cli infra setup                         Deploy the CDK stack
 qc-cli infra setup --no-bootstrap          Deploy without running CDK bootstrap
 qc-cli infra setup --cloudformation-execution-policy <arn> Set CDK bootstrap execution policy ARN
 qc-cli infra status                        Show CDK stack/resource status
+qc-cli infra mlflow-url                    Print a presigned MLflow UI URL
 qc-cli infra destroy                       Destroy stack, retaining S3 data
 qc-cli infra destroy --yes                 Destroy stack without confirmation
 qc-cli infra destroy --delete-bucket-data  Destroy stack and delete S3 data
@@ -140,6 +155,46 @@ qc-cli train list --limit 3     Show a custom number of recent jobs
 
 The expected output artifact is SageMaker’s `model.tar.gz`, normally containing the trained model file your container writes to `/opt/ml/model`.
 
+## Model lifecycle
+
+The CLI uses neutral experiment naming for trained artifacts and reserves release terminology for an explicit promotion step.
+
+Current behavior:
+
+1. `qc-cli train start` submits a SageMaker training job.
+2. `qc-cli train status` finalizes the MLflow run after the job reaches a terminal state.
+3. If the job completed and `mlflow.register_trained_models` is enabled, the SageMaker `model.tar.gz` is registered as a new MLflow model version with:
+   - `qc_cli.stage=experiment`
+   - `qc_cli.artifact_kind=trained_source`
+   - `qc_cli.source=sagemaker`
+4. The MLflow alias `experiment-latest` points at the most recently registered experiment version.
+
+Planned AI Hub extension:
+
+1. AI Hub compile or quantize will create deployable derived artifacts from a trained-source experiment.
+2. Derived artifacts will keep lineage back to the source experiment version instead of replacing it.
+3. Release aliases such as `v1` or `production` will point at the selected deployable artifact.
+
+Example future metadata:
+
+```text
+qc-cli-model version 12
+qc_cli.stage=experiment
+qc_cli.artifact_kind=trained_source
+qc_cli.source=sagemaker
+
+qc-cli-model-aihub version 3
+qc_cli.stage=ai_hub_compiled
+qc_cli.artifact_kind=deployable
+qc_cli.parent_registered_model_name=qc-cli-model
+qc_cli.parent_model_version=12
+qc_cli.runtime=tflite
+qc_cli.quantization=int8
+qc_cli.target_device=Samsung Galaxy S25
+```
+
+In that flow, `experiment-latest` remains a training convenience alias. Release selection is a separate promotion decision based on the derived artifact, not on the experiment name.
+
 ## AWS permissions required
 
 The IAM user or role running the CLI needs: