Agents able to make edits in plan mode

### Describe the bug

I have noticed this issue where the agents can actually edit while being in plan mode. It does so sometimes automatically, which I think is a slight security concern plus also misleading. Unsure if this is an intended feature though

### Affected version

1.0.5

### Steps to reproduce the behavior

1. Switch to plan mode
2. Instead of asking the agent to create a plan specifically, ask it a question that provokes edits
3. You will see it making edits.

### Expected behavior

I'd assume that the agent edit tool call gets rejected and it just prompts me to switch mode as an ideal behavior

### Additional context

_No response_

Reproduce the behavior in plan mode using version 1.0.5: ask a question that provokes edits rather than explicitly requesting a plan. Trace the plan-mode handling and edit tool call, then verify that edit requests are rejected or prompt a mode switch without modifying files.

Scritto dal modello di indicizzazione a partire dal testo della issue.