## Summary
Point synced JavaScript formatting and linting at the repository's own Prettier +
ESLint so CI is the source of truth: add `yarn f` (Prettier), expand the Prettier
globs to all JS-family extensions, and make the CI ESLint step propagate its exit
status instead of swallowing it.

## Changelog
[Internal]

## Test Plan
`yarn lint`, `yarn format-check`, and `yarn f` run from the repo root; the GitHub
`lint` job runs both on this PR.

Changelog: [Internal]

## Summary
Extend yarn-owned formatting to native sources so GitHub CI is the single source
of truth for C/C++/Obj-C and Kotlin, using the OSS toolchain so internal (Meta)
and GitHub produce byte-identical output:

- Add `scripts/lint/clang-format.sh` (pins clang-format `21.1.2` from PyPI) and
  `scripts/lint/ktfmt.sh` (pins ktfmt `0.64` from Maven Central; requires JDK 17+,
  selected from `JAVA_HOME`/PATH). Both derive the file list from `git ls-files`
  and honor the existing vendored/generated exclusions.
- Point `yarn clang-format` + new `yarn clang-format-check`, and `yarn lint-kotlin`
  + `yarn lint-kotlin-check`, at those scripts. `yarn f` now runs Prettier +
  clang-format + ktfmt.
- Run `clang-format-check` and `ktfmt` (Kotlin) in the CI `lint` job (JDK 17 via
  `setup-java`). ktfmt was previously disabled in gradle ("handled inside
  fbsource"); the repo now owns it.
- Reformat 78 Kotlin files that differed under ktfmt `0.64` (meta style: 2-space
  block indent, 4-space continuation, 100 column, keep unused imports).

## Changelog
[Internal]

## Test Plan
`yarn clang-format-check` -> clean; `yarn lint-kotlin-check` (JDK 17) -> clean;
`yarn f` formats JS + native. The GitHub `lint` job runs both native checks on
this PR.

Changelog: [Internal]