- Add DEFAULT_SYSTEM_PROMPT and effectiveSystemPrompt() to ReActAgentComponent
- Block unsupported shell syntax (pipes, redirections, chaining) in ManagedShellCommandTool
- Fix process I/O to prevent hangs when command waits for stdin
- Fix missing sessionId in ReActLoggingHook result log line
- Introduce FakeEchoModel for deterministic local testing
- Add unit tests for ReActAgentComponent, ReActLoggingHook, and shell syntax rejection
- Remove LiveTestSupport credential skip calls from feature tests
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>