feat(opencode): fff search tools

[dmtrKovalenko]

Issue for this PR

Closes #<you guys know right?>

Type of change

• Bug fix
• New feature
• Refactor / code improvement
• Documentation

What does this PR do?

This implements fff pickers for the all file search operation - file search, content search, directories & mixed search.

If you paste a large clearly AI generated description here your PR may be IGNORED or CLOSED!

How did you verify your code works?

bun test
bun dev .
bun run bench-fff.ts

Checklist

• I have tested my changes locally
• I have not included unrelated changes in this PR

If you do not follow this template your PR will be automatically rejected.

[github-actions]

Hey! Your PR title Feat/fff search tools 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:

Based on the search results, I found 2 potentially related PRs that address similar fff search functionality:

1. PR feat: switch file search to fff #18419 - feat: switch file search to fff

   • This PR appears to be about switching file search to use fff, which is directly related to PR feat(opencode): fff search tools #27802's fff search tools implementation.

2. PR feat(search): add runtime-aware search service with fff #23890 - feat(search): add runtime-aware search service with fff

   • This PR implements a runtime-aware search service with fff, which may overlap with the search tools being added in PR feat(opencode): fff search tools #27802.

Why they're related: All three PRs focus on integrating fff (a fuzzy file finder) with the search functionality. PR #27802 implements fff pickers for file search, content search, directories, and mixed search - which could potentially be addressing the same feature set as the earlier PRs.

You may want to check if these earlier PRs were completed, merged, or abandoned to determine if #27802 is a duplicate effort or a continuation/improvement of prior work.

[github-actions]

Thanks for updating your PR! It now meets our contributing guidelines. 👍

[dmtrKovalenko]

this is replaces the truncated message above. Needed because fff doesn't perform the full search once it found requested amount (there could be a bit more if certain file contains a ton of results as the internal pagination is happening over files)

This saves a ton of system resources on large directories when we can reduce amount of syscalls spent on opening and reading files