refactor: Migrate Accessibility Infrastructure from Market Design System (#593)

# Migrate Accessibility Infrastructure from Market Design System

## Overview
This PR migrates accessibility infrastructure components from the market
design system into the Blueprint repository, consolidating accessibility
tooling for Blueprint consumers.

## Changes

### New Module: `BlueprintUIAccessibilityCore`
- Created new Swift package target for accessibility infrastructure
- Migrated accessibility composition and deferral patterns from market
design system
- Added localization support for 12 locales (en, es, fr, ca, ja, pt
variants)
- Included test coverage for accessibility features

### Key Components
- **AccessibilityComposition**: Combines multiple accessibility elements
into unified experiences
- **AccessibilityDeferral**: Enables content inheritance patterns for
form fields and containers
- **AccessibilitySetter**: Element wrapper for applying accessibility
properties with composition
- **Localized strings infrastructure** with extraction tooling
- **Extensions and utilities** for accessibility traits and custom
actions

### BlueprintUICommonControls Updates
- **Reorganized accessibility files** into dedicated `Accessibility/`
directory
- **Added AccessibilityCombine**: Element wrapper that uses the new
composition infrastructure
- **Added AccessibilityModifiers**: Convenience methods that leverage
the new core functionality
- **Updated existing accessibility elements** to integrate with the new
module
- **Maintained backwards compatibility** for all existing accessibility
APIs

### Dependencies Updated
- Modified `BlueprintUICommonControls` to depend on
`BlueprintUIAccessibilityCore`
- Updated `Package.swift` to include the new accessibility core target
- Enhanced build configuration with resource handling for localized
strings

### Developer Tooling
- Added string extraction script (`Scripts/extract_english_strings.sh`)
- Included comprehensive documentation in
`BlueprintUIAccessibilityCore/README.md`
- Updated project configuration for Xcode and Tuist

## Files Modified

### New Module Structure
```
BlueprintUIAccessibilityCore/
├── README.md
├── Sources/
│   ├── AccessibilityComposition.swift
│   ├── AccessibilityDeferral.swift
│   ├── AccessibilitySetter.swift
│   ├── LocalizedStrings.swift
│   └── Extensions/
│       ├── AccessibilityTraits+Extensions.swift
│       ├── Array+Extensions.swift
│       ├── Optional+Extensions.swift
│       └── UIAccessibilityCustomAction+Extensions.swift
├── Tests/
│   └── AccessibilityCompositionTests.swift
└── Resources/ (12 localization directories)
```

### BlueprintUICommonControls Changes
```
BlueprintUICommonControls/Sources/Accessibility/
├── AccessibilityBlocker.swift          (moved)
├── AccessibilityContainer.swift        (moved)
├── AccessibilityElement.swift          (moved)
├── AccessibilityFocus.swift            (moved)
├── AccessibilityLargeContentViewer.swift (moved)
├── AccessibilityCombine.swift          (new)
└── AccessibilityModifiers.swift        (new)
```

## Rationale
- Consolidates accessibility tooling previously distributed across
repositories
- Makes accessibility patterns available to all Blueprint consumers
- Improves maintainability through centralized infrastructure
- Enables consistent testing and documentation

## Testing
- All existing tests continue to pass
- Localization strings validated
- Module dependencies verified

## Breaking Changes
None. This change is additive and does not affect existing Blueprint
functionality.

---------

Co-authored-by: johnnewman-square <[email protected]>
Co-authored-by: Soroush Khanlou <[email protected]>
Co-authored-by: Claude <[email protected]>

Author: 4 people

BlueprintUIAccessibilityCore/README.md

@@ -0,0 +1,18 @@
+/* A label for accessibility custom content that indicates that an associated string is an error message. */
+"accessibility_error_label" = "Error";
+
+/* The default accessibility label for '-' button in Stepper. This button should decrease the value of the stepper. */
+"stepper_decrement" = "Redueix";
+
+/* The default accessibility label for '+' button in Stepper. This button should increase the value of the stepper. */
+"stepper_increase" = "Incrementa";
+
+/* Accessibility label describing a checkbox that is neither checked nor unchecked, but 'mixed' - it displays a dash instead of a check. */
+"toggle_mixed" = "Combinat";
+
+/* Accessibility label describing a checkbox or switch that is unchecked or off */
+"toggle_off" = "Desactivat";
+
+/* Accessibility label describing a checkbox or switch that is checked or on. */
+"toggle_on" = "Activat";
+

BlueprintUIAccessibilityCore/Resources/ca-ES.lproj/Localizable.strings

@@ -0,0 +1,18 @@
+/* A label for accessibility custom content that indicates that an associated string is an error message. */
+"accessibility_error_label" = "Error";
+
+/* The default accessibility label for '-' button in Stepper. This button should decrease the value of the stepper. */
+"stepper_decrement" = "Decrement";
+
+/* The default accessibility label for '+' button in Stepper. This button should increase the value of the stepper. */
+"stepper_increase" = "Increment";
+
+/* Accessibility label describing a checkbox that is neither checked nor unchecked, but 'mixed' - it displays a dash instead of a check. */
+"toggle_mixed" = "Mixed";
+
+/* Accessibility label describing a checkbox or switch that is unchecked or off */
+"toggle_off" = "Off";
+
+/* Accessibility label describing a checkbox or switch that is checked or on. */
+"toggle_on" = "On";
+

BlueprintUIAccessibilityCore/Resources/en-AU.lproj/Localizable.strings

@@ -0,0 +1,18 @@
+/* A label for accessibility custom content that indicates that an associated string is an error message. */
+"accessibility_error_label" = "Error";
+
+/* The default accessibility label for '-' button in Stepper. This button should decrease the value of the stepper. */
+"stepper_decrement" = "Decrement";
+
+/* The default accessibility label for '+' button in Stepper. This button should increase the value of the stepper. */
+"stepper_increase" = "Increment";
+
+/* Accessibility label describing a checkbox that is neither checked nor unchecked, but 'mixed' - it displays a dash instead of a check. */
+"toggle_mixed" = "Mixed";
+
+/* Accessibility label describing a checkbox or switch that is unchecked or off */
+"toggle_off" = "Off";
+
+/* Accessibility label describing a checkbox or switch that is checked or on. */
+"toggle_on" = "On";
+

BlueprintUIAccessibilityCore/Resources/en-CA.lproj/Localizable.strings

@@ -0,0 +1,18 @@
+/* A label for accessibility custom content that indicates that an associated string is an error message. */
+"accessibility_error_label" = "Error";
+
+/* The default accessibility label for '-' button in Stepper. This button should decrease the value of the stepper. */
+"stepper_decrement" = "Decrement";
+
+/* The default accessibility label for '+' button in Stepper. This button should increase the value of the stepper. */
+"stepper_increase" = "Increment";
+
+/* Accessibility label describing a checkbox that is neither checked nor unchecked, but 'mixed' - it displays a dash instead of a check. */
+"toggle_mixed" = "Mixed";
+
+/* Accessibility label describing a checkbox or switch that is unchecked or off */
+"toggle_off" = "Off";
+
+/* Accessibility label describing a checkbox or switch that is checked or on. */
+"toggle_on" = "On";
+

BlueprintUIAccessibilityCore/Resources/en-GB.lproj/Localizable.strings

@@ -0,0 +1,18 @@
+/* A label for accessibility custom content that indicates that an associated string is an error message. */
+"accessibility_error_label" = "Error";
+
+/* The default accessibility label for '-' button in Stepper. This button should decrease the value of the stepper. */
+"stepper_decrement" = "Decrement";
+
+/* The default accessibility label for '+' button in Stepper. This button should increase the value of the stepper. */
+"stepper_increase" = "Increment";
+
+/* Accessibility label describing a checkbox that is neither checked nor unchecked, but 'mixed' - it displays a dash instead of a check. */
+"toggle_mixed" = "Mixed";
+
+/* Accessibility label describing a checkbox or switch that is unchecked or off */
+"toggle_off" = "Off";
+
+/* Accessibility label describing a checkbox or switch that is checked or on. */
+"toggle_on" = "On";
+

BlueprintUIAccessibilityCore/Resources/en-IE.lproj/Localizable.strings

@@ -0,0 +1,18 @@
+/* A label for accessibility custom content that indicates that an associated string is an error message. */
+"accessibility_error_label" = "Error";
+
+/* Accessibility action to decrement a value */
+"Decrement" = "Decrement";
+
+/* Accessibility action to increment a value */
+"Increment" = "Increment";
+
+/* Accessibility value for a toggle button in a mixed state */
+"Mixed" = "Mixed";
+
+/* Accessibility value for a toggle button in the off state */
+"Off" = "Off";
+
+/* Accessibility value for a toggle button in the on state */
+"On" = "On";
+

BlueprintUIAccessibilityCore/Resources/en.lproj/Localizable.strings

@@ -0,0 +1,18 @@
+/* A label for accessibility custom content that indicates that an associated string is an error message. */
+"accessibility_error_label" = "Error";
+
+/* The default accessibility label for '-' button in Stepper. This button should decrease the value of the stepper. */
+"stepper_decrement" = "Disminuir";
+
+/* The default accessibility label for '+' button in Stepper. This button should increase the value of the stepper. */
+"stepper_increase" = "Aumentar";
+
+/* Accessibility label describing a checkbox that is neither checked nor unchecked, but 'mixed' - it displays a dash instead of a check. */
+"toggle_mixed" = "Combinación";
+
+/* Accessibility label describing a checkbox or switch that is unchecked or off */
+"toggle_off" = "Desactivada";
+
+/* Accessibility label describing a checkbox or switch that is checked or on. */
+"toggle_on" = "Activada";
+

BlueprintUIAccessibilityCore/Resources/es-ES.lproj/Localizable.strings

@@ -0,0 +1,18 @@
+/* A label for accessibility custom content that indicates that an associated string is an error message. */
+"accessibility_error_label" = "Error";
+
+/* The default accessibility label for '-' button in Stepper. This button should decrease the value of the stepper. */
+"stepper_decrement" = "Disminución";
+
+/* The default accessibility label for '+' button in Stepper. This button should increase the value of the stepper. */
+"stepper_increase" = "Aumento";
+
+/* Accessibility label describing a checkbox that is neither checked nor unchecked, but 'mixed' - it displays a dash instead of a check. */
+"toggle_mixed" = "Combinado";
+
+/* Accessibility label describing a checkbox or switch that is unchecked or off */
+"toggle_off" = "Desactivado";
+
+/* Accessibility label describing a checkbox or switch that is checked or on. */
+"toggle_on" = "Activado";
+

BlueprintUIAccessibilityCore/Resources/es.lproj/Localizable.strings

@@ -0,0 +1,18 @@
+/* A label for accessibility custom content that indicates that an associated string is an error message. */
+"accessibility_error_label" = "Erreur";
+
+/* The default accessibility label for '-' button in Stepper. This button should decrease the value of the stepper. */
+"stepper_decrement" = "Diminution";
+
+/* The default accessibility label for '+' button in Stepper. This button should increase the value of the stepper. */
+"stepper_increase" = "Augmentation";
+
+/* Accessibility label describing a checkbox that is neither checked nor unchecked, but 'mixed' - it displays a dash instead of a check. */
+"toggle_mixed" = "Mixte";
+
+/* Accessibility label describing a checkbox or switch that is unchecked or off */
+"toggle_off" = "Désactivé";
+
+/* Accessibility label describing a checkbox or switch that is checked or on. */
+"toggle_on" = "Activé";
+