[FEATURE]: Add tui.tips configuration option to disable input placeholder hints

[jowitte]

Feature description

Add a tui.tips configuration option to opencode.json that allows users to disable the placeholder hints ("Ask anything: Ask a question, move files, explore your code...") in the input field.

Current behavior

The tips can only be toggled via keybind (<leader>h / Ctrl+X H). While this works and persists across restarts, it would be more convenient to configure this in opencode.json, especially for:

• Users who prefer declarative configuration over runtime toggles
• Sharing configurations across machines (opencode.json is typically version-controlled)
• Corporate/team setups where consistent UX is desired

Proposed solution

Add a tips property to the tui configuration section:

{
  "$schema": "https://opencode.ai/config.json",
  "tui": {
    "scroll_speed": 3,
    "tips": false
  }
}

Alternatives considered

The current keybind approach works but requires manual action on each new installation/machine.

Additional context

The tui section already supports scroll_speed, scroll_acceleration, and diff_style. Adding tips would follow the same pattern for UI customization options.

[github-actions]

This issue might be a duplicate of existing issues. Please check:

• TUI:"Disable/Enable animations" ought be available in the command_list prior to session beginning #10495: [FEATURE]: TUI settings like "Disable/Enable animations" should be configurable and available before session starts
• [Feature Request] Add config option to disable copy-on-select behavior #10490: [Feature Request] Add config option to disable copy-on-select behavior
• [FEATURE]: Hide thinking blocks with configuration toggle #10470: [FEATURE]: Hide thinking blocks with configuration toggle

All of these are feature requests asking for similar tui configuration options in opencode.json to control TUI behavior. While your request is specifically for the tui.tips option, these issues show a pattern of requests for more TUI customization options, which could potentially be addressed together.

Feel free to ignore if your request specifically requires the tips configuration.