fix: bump minimum Flutter SDK to 3.27.0 to fix TapRegionUpCallback not found ( #227, #229)

[mem-5514-tahara]

Hi @Tkko 👋 Thanks again for your continuous work on this package!
I'm submitting this PR to fix the compilation issues reported by users on older Flutter versions.

Problem

Users on Flutter 3.24.x and earlier encounter a compile-time error when using this package:

Error: Type 'TapRegionUpCallback' not found.
lib/src/pinput.dart:461:9: final TapRegionUpCallback? onTapUpOutside;

Error: No named parameter with the name 'onTapUpOutside'.
lib/src/pinput_state.dart:432:11: onTapUpOutside: widget.onTapUpOutside,

Root Cause

TapRegionUpCallback and EditableText.onTapUpOutside were introduced in Flutter 3.27.0 via flutter/flutter#156110 — merged on 2024-10-21, included in the Flutter 3.27.0 stable release (tagged 2024-12-10).

The pubspec.yaml SDK constraint was flutter: ">=3.7.0", which allowed users on older Flutter versions to install the package and hit this compile error at build time.

Affected code

File	Line	Code
lib/src/pinput.dart	461	final TapRegionUpCallback? onTapUpOutside;
lib/src/pinput_state.dart	432	onTapUpOutside: widget.onTapUpOutside,
pubspec.yaml	23	flutter: ">=3.7.0" ← too permissive

Fix

Raise the minimum Flutter SDK constraint to match the version that introduced the type:

# Before
flutter: ">=3.7.0"

# After
flutter: ">=3.27.0"

Users on incompatible Flutter versions will now receive a clear version conflict message from the package resolver instead of an opaque compile-time type error.

⚠️ Breaking Change / Versioning Note

Bumping the minimum Flutter SDK constraint from 3.7.0 to 3.27.0 is a significant jump. While it correctly reflects the required framework APIs, it acts as a breaking change for users who are still on older Flutter versions.

Depending on your versioning strategy, you might want to consider publishing this change as a major version bump to adhere to semantic versioning and avoid unexpectedly breaking CI pipelines for existing users.

Alternatives Considered

Option	Reason rejected
Remove onTapUpOutside parameter	Breaking change — removes an existing feature
Define a local typedef for the callback	Dart has no conditional compilation; the local typedef would conflict with the framework type on Flutter ≥ 3.27.0

Related Issues

• Closes Error: Type 'TapRegionUpCallback' not found. #227
• Closes Error: Type 'TapRegionUpCallback' not found. #229