Bash tool overrides are not honored in the latest Copilot SDK/runtime

## Description

Custom overrides for the Bash tool family are not honored with Copilot SDK `1.0.13` and `@github/copilot@1.0.83`.

The custom handlers for `bash`, `read_bash`, `stop_bash`, and `list_bash` are never invoked. File and search tool overrides work correctly under the same configuration.

## Versions tested

- Copilot SDK: `1.0.13`
- CLI/runtime: `@github/copilot@1.0.83`

The issue reproduces with both the SDK’s default entry point and the full CLI launched through `index.js`.

## Steps to reproduce

1. Register custom tools named `bash`, `read_bash`, `stop_bash`, and `list_bash`, with override enabled.
2. Add logging or invocation counters to each custom handler.
3. Register a `create` override as a control.
4. Create a session and invoke the tools.
5. Observe that the `create` handler is called, but the Bash tool handlers are not.

The issue also reproduces when invoking `bash` directly through `session.tools.execute`, without model involvement.

## Expected behavior

Overridden tools should use the custom tool schemas and invoke the registered custom handlers.

## Actual behavior

| Tools | Override behavior |
|---|---|
| `view`, `create`, `edit` | Works as expected |
| `glob`, `grep`, `apply_patch` | Works as expected |
| `bash` | Custom handler is not invoked |
| `read_bash` | Custom handler is not invoked; built-in parameter validation is used instead of the custom schema |
| `stop_bash` | Custom handler is not invoked; built-in parameter validation is used instead of the custom schema |
| `list_bash` | Custom handler is not invoked |

## Additional evidence

The tool-planning logic recognizes the overrides:

{
"validOverridingExternalToolNames": ["bash", "create"]
}

However, only the `create` override takes effect. The `bash` override is recognized but not honored during execution.

Could you confirm whether overriding the Bash tool family is still supported, and investigate why these overrides are not taking effect?

Reproduce the issue with Copilot SDK 1.0.13 and @github/copilot 1.0.83 using the SDK entry point and the full CLI through index.js. Compare session.tools.execute for bash, read_bash, stop_bash, and list_bash with the working create override, then trace how recognized overrides reach execution. Done means each Bash override uses its custom schema and invokes its registered handler.

Written by the indexing model from the issue text.