…ect (#11941)

Adds a pre-commit hook that you can install to verify that `dart analyze --fatal-infos` and the package format are correct when you make a call to `git commit`. Intended to ensure agents commit code that meets are quality standards.

Also makes the following updates the plugins tool:

- Adds `--run-on-staged-packages` flag that allows the command to only run on files with staged changes. This flag cannot be run with any other flags that filter packages where the command runs (like `--run-on-dirty-packages`)
- Adds optimization to the format tool to avoid invoking native tool chains to format when non-native files are modified

Miscellaneous notes:

- `script/githooks/bin/install_hooks.dart` is the script to install the hook that devs would need to run to use it.
- I modeled the new `githooks` directory like https://github.com/flutter/flutter/tree/master/engine/src/flutter/tools/githooks to make it easier for folks to add new hooks

## Pre-Review Checklist

**Note**: The Flutter team is currently trialing the use of [Gemini Code Assist for GitHub](https://developers.google.com/gemini-code-assist/docs/review-github-code). Comments from the `gemini-code-assist` bot should not be taken as authoritative feedback from the Flutter team. If you find its comments useful you can update your code accordingly, but if you are unsure or disagree with the feedback, please feel free to wait for a Flutter team member's review for guidance on which automated comments should be addressed.

[^1]: Regular contributors who have demonstrated familiarity with the repository guidelines only need to comment if the PR is not auto-exempted by repo tooling.

The web Dart unit tests are currently some of our slowest tests, and shard 2 is on the brink of hitting the 60 minute timeout. This is the first half of the process of switching from 2 shards to three shards, adding the new tasks in bringup mode but not yet changing the existing shards. Once this lands and propagates, a second PR will switch to actually using three shards.

This brings us closer to our limit of 100 post-submit tasks for our wait-for-release action, but doesn't yet cross it (and we expect that limit to stop being an issue soon).

Takes the new shard out of bring-up, and adjusts the existing shards to expect three shards rather than two.

…OS permissions (#11901)

Clarifies the `getAvailableBiometrics` docstring to explain that it returns biometrics available for the app to use, which may not include all enrolled biometrics (e.g., if iOS permission has not been granted).

Fixes: flutter/flutter#187512

## Pre-Review Checklist

**Note**: The Flutter team is currently trialing the use of [Gemini Code Assist for GitHub](https://developers.google.com/gemini-code-assist/docs/review-github-code). Comments from the `gemini-code-assist` bot should not be taken as authoritative feedback from the Flutter team. If you find its comments useful you can update your code accordingly, but if you are unsure or disagree with the feedback, please feel free to wait for a Flutter team member's review for guidance on which automated comments should be addressed.

[^1]: Regular contributors who have demonstrated familiarity with the repository guidelines only need to comment if the PR is not auto-exempted by repo tooling.

### Exceptions
- **Test Exemption**: This PR is exempt from testing because it is a documentation-only change.

…12123)

The default implementation of `setJpegImageQuality` threw `UnimplementedError`, but there is no support-query API for it, so a client has no way to know whether it is safe to call (raised in review of #11155). JPEG quality is a best-effort setting, so this changes the default to a no-op: platforms that support it override the method, and platforms that don't (e.g. web) simply ignore it.

…12124)

Adds `backBufferDurationMs` to `video_player_android`

This PR has only the android package changes from the main PR: #11810.

Following PR split as per [Changing federated plugins](https://github.com/flutter/flutter/blob/master/docs/ecosystem/contributing/README.md#changing-federated-plugins)

## Pre-Review Checklist