CLI scaffold generates template incompatible with latest a2a-sdk: ModuleNotFoundError: No module named 'a2a.server.apps'

[BEASTSHRIRAM]

Description

Bug Description

AgentCore CLI scaffold generates a main.py template that uses
a2a.server.apps.A2AStarletteApplication which does not exist
in the latest a2a-sdk versions, causing an immediate crash on
agentcore dev.

Environment

• OS: Windows 11
• Python: 3.13
• bedrock-agentcore: 1.8.0
• a2a-sdk: 0.2.x

Additional Context

• a2a.server.apps module does not exist in current a2a-sdk
• Earlier error also seen: ImportError: cannot import name 'new_task' from 'a2a.utils'
• Both errors indicate scaffold template is pinned to an older
  a2a-sdk API that has since changed
• pyproject.toml specifies a2a-sdk >= 0.2.0 but
  the imported modules don't exist in that version

Suggested Fix

Either:

1. Pin a2a-sdk to the exact version compatible with current
   scaffold template
2. Update scaffold template imports to match latest a2a-sdk API
3. Add version compatibility check in agentcore init command

Steps to Reproduce

Steps to Reproduce

1. agentcore init MyAgent
2. cd into project
3. agentcore dev

Expected Behavior

Expected Behavior

agentcore dev should run successfully after scaffolding.

Actual Behavior

Error

ModuleNotFoundError: No module named 'a2a.server.apps'
File "bedrock_agentcore\runtime\a2a.py", line 207, in build_a2a_app
    from a2a.server.apps import A2AStarletteApplication

CLI Version

0.13.0

Operating System

Windows