[in_app_purchase_storekit] Add Transaction.unfinished API and expose …

…appAccountToken (#10439)

## Summary

Adds two new StoreKit 2 features to `in_app_purchase_storekit`:

- `SK2Transaction.unfinishedTransactions()` - Queries only unfinished transactions for better performance
- `SK2PurchaseDetails.appAccountToken` - Exposes user UUID for backend integration

## Motivation

1. **Performance:** Developers often only need unfinished transactions to complete them, not all historical transactions. This mirrors Apple's official `Transaction.unfinished` API.
2. **User Identification:** The ability to set `appAccountToken` already exists when making purchases, but reading it back from transaction details was missing.

## Changes

- Added pigeon interface method for `unfinishedTransactions()`
- Implemented Swift native code using Apple's `Transaction.unfinished` API
- Exposed `appAccountToken` property in `SK2PurchaseDetails`
- Added unit tests for both features

## Breaking Changes

None. Both features are additive and maintain full backward compatibility.

[rfw] Add Flexible widget support to core widgets (#9750)

# [rfw] Add Flexible widget support

This PR adds support for the `Flexible` widget to Remote Flutter Widgets (RFW), allowing developers to create flexible layouts with both loose and tight fitting behavior.

Fixes [#173313](flutter/flutter#173313)

The `Flexible` widget provides more granular control over flex layouts compared to the existing `Expanded` widget:
- **FlexFit.loose**: Widget takes only the space it needs (default)
- **FlexFit.tight**: Widget takes all available space (same as Expanded)

**Implementation:**
- Added `Flexible` widget to `lib/src/flutter/core_widgets.dart`
- Supports `flex` (default: 1) and `fit` parameters (loose/tight, default: loose)
- Uses existing `ArgumentDecoders.enumValue` pattern for FlexFit parsing
- Maintains alphabetical ordering and follows existing RFW patterns
- Added comprehensive test coverage in `test/core_widgets_test.dart`
- Refactored tests based on code review feedback to reduce duplication

**Usage Example:**
```rfwtxt
import core.widgets;

widget FlexibleDemo = Column(
  children: [
    Flexible(
      flex: 1,
      fit: "loose",
      child: Text(text: "Takes needed space"),
    ),
    Flexible(
      flex: 2,
      fit: "tight", 
      child: Text(text: "Takes all available space"),
    ),
  ],
);
```

**API Compatibility:**
Follows Flutter's `Flexible` widget API exactly:
- `flex: int` (default: 1)
- `fit: FlexFit` (loose/tight, default: loose)  
- `child: Widget` (required)

## Pre-Review Checklist

[go_router] Fixes an issue where `onEnter` blocking causes navigation…

… stack loss (stale state restoration) (#10476)

*Replace this paragraph with a description of what this PR is changing or adding, and why. Consider including before/after screenshots.*

*List which issues are fixed by this PR. You must list at least one issue.*
Fixes flutter/flutter#178853

## Pre-Review Checklist

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[^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.

[shared_preferences_tool] Update dependencies and fix deprecation (#1…

…0560)

Update the dependencies and fix deprecations.

Issues:

flutter/flutter#166602

## 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.

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[camera_android_camerax] Updates pigeon generation to prevent crash w…

…hen objects call to Dart after a hot restart (#10571)

Fixes flutter/flutter#176451

## 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.

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[camera_android_camerax] Removes internal native library Dart proxy (#…

…10536)

ProxyApis now
* Generate a Dart `PigeonOverrides` class that can override constructors and static methods.
* Use a test `PigeonInstanceManager` that doesn't make any message calls.

This removes the manually written proxy and replaces its use in tests with `PigeonOverrides`. 

## 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.

[webview_flutter_wkwebview] Removes internal native library Dart proxy (

#10528)

Removes internal native library Dart proxy and updates test with generated PigeonOverrides. Also removes unnecessary test InstanceManagers.

## 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.

[webview_flutter_android] Removes internal native library Dart proxy (#…

…10527)

Removes internal native library Dart proxy and updates test with generated PigeonOverrides. Also removes unnecessary test InstanceManagers.

## 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.

[pigeon] Fixes crash that occurs when an object that is removed from …

…the instance manager calls to Dart (#10552)

In the event of a hot restart, the native `InstanceManagers` are cleared. There is then a chance for a class to make a callback when it is no in the instance manager which leads to a null exception in the codec.

Part of fixing flutter/flutter#176451
Pigeon side fix for #10529

## Pre-Review Checklist

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[pigeon] Fixes error from constructor parameter sharing name with att…

…ached field for a ProxyApi (#10541)

Attached parameters aren't passed in constructor message call so they can share name with constructor parameter. 

## 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.