Allow terminal_tool command output truncation limit to be configurable

[vimota]

Currently output is truncated to 16kb: https://github.com/zed-industries/zed/blob/main/crates/assistant_tools/src/terminal_tool.rs#L27C7-L27C27

So doing something like git diff main gets truncated if there are a lot of changes. Ideally users could configure their profile tools to set the truncation limit. Or instead just set limits on per response total token count to prevent any sort of runaway token usage.

[dcamsiteimprove]

+1 on this.
I'm also using the agent with git diff to do a pre-code-review check.
Github copilot has an unlimited-token tier, so token usage is not a concern for me. Also for people running their own self-hosted models this limit doesn't really apply.
It'd be great to get asked "do you really want to send this much output to the agent?", or at least allow to customize this limit in the settings...