[BUG] Incorrect reference in invoke and status help text

**Describe the bug**
The help text for the invoke and status commands describes the --agent flag as `Agent name (use 'bedrock_agentcore configure list' to see available)` where it should be use 'agentcore configure list'.

**To Reproduce**
```bash
agentcore invoke --help
agentcore status --help
```

**Expected behavior**
Should say `agentcore configure list`

**Error Output**
```
Agent name (use 'bedrock_agentcore configure list' to see available)
```

**Environment:**
- OS: Mac Tahoe 26.2
- Python version: 3.13.4
- Package version: 0.2.5
- Installation method: pip

**Additional context**
These are the only two places.
1. https://github.com/aws/bedrock-agentcore-starter-toolkit/blob/165496eeb877ff7bb514891e2779b5fd94140df9/src/bedrock_agentcore_starter_toolkit/cli/runtime/commands.py#L699
2. https://github.com/aws/bedrock-agentcore-starter-toolkit/blob/165496eeb877ff7bb514891e2779b5fd94140df9/src/bedrock_agentcore_starter_toolkit/cli/runtime/commands.py#L861

Open src/bedrock_agentcore_starter_toolkit/cli/runtime/commands.py at the two locations linked in the issue, around lines 699 and 861. Run `agentcore invoke --help` and `agentcore status --help` before and after the change. Done means both --agent help messages refer to `agentcore configure list` rather than `bedrock_agentcore configure list`.

Written by the indexing model from the issue text.