Adding keymaps to config file

[jpoz]

This PR allows users to override default keymaps:

{
  "data": {},
  "tui": {
    "theme": "opencode"
  },
  "shell": {},
  "keyMaps": {
    "chat": {
      "toggleTools": [
        "ctrl+b"
      ]
    }
  }
}

It also updates the help dialog:

And the bar above the message input:

[adamdotdevin]

hey, sorry for being slow, on vacation this week. i'm hesitant to merge anything that touches config while #38 is in progress, we're rewriting all of the config stuff (and the backend) in typescript. let me discuss with dax and circle back. really appreciate the PR, we definitely want keymaps to be configurable!

[jpoz]

@adamdottv oh wow. what's the motivation to move from go -> ts?

[adamdotdevin]

to be clear, the TUI will continue as a go app (with bubbletea), there will just be a clearer separation of client/server. and there were a bunch of factors, but leveraging the AI SDK to reduce scope and eliminate all provider related bugs/changes was a big one.

[jpoz]

Interesting, I was surprised ya'll are writing that yourself instead of using something like https://github.com/tmc/langchaingo/tree/main/llms

Lmk how I can help

[thdxr]

closing as we rewrote the codebase - appreciate it though!