feat: add keyboard shortcut to toggle thinking visibility

[BackSlasher]

What does this PR do?

Thinking can be toggled via command, but not via keyboard shortcut. Now it can.
Default shortcut: ctrl+alt+t.
Shortcut name: thinking_toggle

How did you verify your code works?

Ran locally using bun dev, asked it what's the best apple

Without thinking:

After ctrl+alt+t:

Fixes #8167

[github-actions]

Hey! Your PR title [EASY] feat: add keyboard shortcut to toggle thinking visibility doesn't follow conventional commit format.

Please update it to start with one of:

• feat: or feat(scope): new feature
• fix: or fix(scope): bug fix
• docs: or docs(scope): documentation changes
• chore: or chore(scope): maintenance tasks
• refactor: or refactor(scope): code refactoring
• test: or test(scope): adding or updating tests

Where scope is the package name (e.g., app, desktop, opencode).

See CONTRIBUTING.md for details.

[github-actions]

The following comment was made by an LLM, it may be inaccurate:

Potential Duplicate Found:

• PR feat(opencode): add keybind for /thinking toggle #8168: feat(opencode): add keybind for /thinking toggle

Why it's related: PR #8168 appears to be addressing the exact same feature - adding a keyboard keybind to toggle the /thinking command. This is likely a duplicate or a related PR that should be consolidated.

[github-actions]

Thanks for your contribution!

This PR doesn't have a linked issue. All PRs must reference an existing issue.

Please:

1. Open an issue describing the bug/feature (if one doesn't exist)
2. Add Fixes #<number> or Closes #<number> to this PR description

See CONTRIBUTING.md for details.

[BackSlasher]

It's indeed a dup of #8168, solves #8167

[BackSlasher]

(feel free to close this if merging the other)