feat(core) Add login to shell_command tool (#6846)

## Summary
Adds the `login` parameter to the `shell_command` tool - optional,
defaults to true.

## Testing
- [x] Tested locally

AGENTS.md

@@ -75,6 +75,7 @@ If you don’t have the tool:
 ### Test assertions
 
 - Tests should use pretty_assertions::assert_eq for clearer diffs. Import this at the top of the test module if it isn't already.
+- Prefer deep equals comparisons whenever possible. Perform `assert_eq!()` on entire objects, rather than individual fields.
 
 ### Integration tests (core)