[BUG] Region issue: 'us-east-2' is not a recognized Bedrock region.

**Describe the bug**
We are attempting to migrate an existing Amazon Bedrock Agent to the new Bedrock AgentCore platform using the bedrock-agentcore-starter-toolkit.
The bedrock-agentcore-starter-toolkit utility does not recognize or support the us-east-2 region.

**To Reproduce**
agentcore import-agent \
--region us-east-2 \
--agent-id YEV2QSUSF7 \
--agent-alias-id VIIEK6HAL9 \
--target-platform strands \
--output-dir ./my-ohio-agent \
--deploy-runtime \
--run-option runtime

Error:
The utility produced the following warning and failed to proceed with the import:

Warning: 'us-east-2' is not a recognized Bedrock region.
Proceeding with region selection.

**Expected behavior**
Ohio (us-east-2) should be a valid Region to work with.

**Error Output**
```
╭──────────────────────────────────────────────────────────────────────────────────────────────────────────╮
│ Bedrock Agent Translation Tool │
╰───────────── Convert your Bedrock Agent to LangChain/Strands code with AgentCore Primitives ─────────────╯
╭───────────────────────────────────────────── Region Warning ─────────────────────────────────────────────╮
│ Warning: 'us-east-2' is not a recognized Bedrock region. │
│ Proceeding with region selection. │
╰──────────────────────────────────────────────────────────────────────────────────────────────────────────╯

Select an AWS region for Bedrock Agents:
? Select a region: (Use arrow keys)
» US East (N. Virginia) (us-east-1)
US West (Oregon) (us-west-2)
AWS GovCloud (US-West) (us-gov-west-1)
Asia Pacific (Tokyo) (ap-northeast-1)
Asia Pacific (Mumbai) (ap-south-1)
Asia Pacific (Singapore) (ap-southeast-1)
Asia Pacific (Sydney) (ap-southeast-2)
Canada (Central) (ca-central-1)
Europe (Frankfurt) (eu-central-1)
Europe (Zurich) (eu-central-2)
Europe (Ireland) (eu-west-1)
Europe (London) (eu-west-2)
Europe (Paris) (eu-west-3)
South America (São Paulo) (sa-east-1)
```

**Environment:**
AWS Account ID: #### (I can share it if needed)
Region of Bedrock Agent: US East (Ohio) (us-east-2)
Execution Environment: AWS CloudShell (using Amazon Linux 2)
Python Version: Python 3.11 (installed via pyenv due to toolkit requirement)
Toolkit Version: bedrock-agentcore-starter-toolkit (0.2.5)

Start with the `agentcore import-agent` command shown in the issue and trace the Bedrock region validation and selection list. The work is done when `us-east-2` is recognized and the import proceeds without the region warning; no specific source file or test is named in the report.

Written by the indexing model from the issue text.