Feature request: option to disable automatic EnterPlanMode

What feature would you like to see?

The agent sometimes calls the EnterPlanMode tool on its own initiative — without me ever requesting Plan Mode. For example:

● I'll plan this out first — it's a multi-file setup with a few toolchain decisions to make.
● Used EnterPlanMode

This unilaterally switches my session into Plan Mode, which:

• Interrupts the flow. I asked for the task to be done, not for a plan review. Now I have to approve/reject a plan before anything happens — an extra round-trip I never opted into.
• Overrides my permission-mode choice. If I wanted planning, I would toggle Plan Mode myself. The mode switch is a user-level decision; the model shouldn't make it for me.
• Is unpredictable. Whether a task triggers auto-planning depends on the model's judgment of "non-trivial", so identical workflows behave differently run to run.

Proposed solution

At minimum, provide a config option to disable the agent-initiated EnterPlanMode, e.g. in config.toml:

# Never let the model enter Plan Mode on its own;
# Plan Mode is only entered when the user toggles it explicitly.
auto_plan_mode = false

Additional information

No response

Start by locating the configuration handling for config.toml and the EnterPlanMode tool invocation. Determine how to distinguish agent-initiated entry from an explicit user toggle, then verify that auto_plan_mode = false prevents only the automatic path while preserving manual Plan Mode entry.