Add PR validation summary, review, and Appium test script

Adds PR-Creation-Summary.md and PR32939-Review.md documenting the validation and review of PR dotnet#32939 (Slider/Stepper property order fix), and introduces RunWithAppiumTest.cs for automated Appium-based UI testing of the fix in the Sandbox app.

Author: kubaflo

CustomAgentLogsTmp_/PR-Creation-Summary.md

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+# PR Creation Summary
+
+## Branch Information
+
+**Branch**: `sandbox-pr32939-validation`  
+**Base**: `fix/slider-stepper-property-order-independence` (PR #32939)  
+**Repository**: kubaflo/maui  
+**Pushed**: ✅ Success
+
+**Create PR URL**: https://github.com/kubaflo/maui/pull/new/sandbox-pr32939-validation
+
+---
+
+## PR Title
+
+```
+[Sandbox] Add test scenario for PR #32939 - Slider/Stepper property order fix validation
+```
+
+---
+
+## PR Description
+
+```markdown
+> [!NOTE]
+> Are you waiting for the changes in this PR to be merged?
+> It would be very helpful if you could [test the resulting artifacts](https://github.com/dotnet/maui/wiki/Testing-PR-Builds) from this PR and let us know in a comment if this change resolves your issue. Thank you!
+
+## Description
+
+This PR adds a comprehensive Sandbox test scenario to validate PR #32939's fix for Slider and Stepper property order independence issues.
+
+The test scenario reproduces issue #32903 and validates that the fix correctly preserves the `Value` property regardless of the order in which `Minimum`, `Maximum`, and `Value` are set (via XAML bindings or programmatically).
+
+## Test Coverage
+
+The Sandbox app demonstrates and validates:
+
+1. **XAML Binding Scenario** (Issue #32903 reproduction)
+   - ViewModel with: `ValueMin=10`, `ValueMax=100`, `Value=50`
+   - Slider and Stepper bound to these properties
+   - Validates that Value=50 is preserved regardless of binding order
+
+2. **Programmatic Property Order Tests**
+   - 3 button-triggered tests covering different property setting orders:
+     - Value → Minimum → Maximum
+     - Minimum → Value → Maximum
+     - Maximum → Value → Minimum
+   - Each test validates that Value=50 is correctly preserved
+
+3. **Dynamic Range Changes** (Value Preservation)
+   - Shrink range to 0-10 (Value clamped to 10)
+   - Expand range back to 0-100
+   - Validates that Value restores to original 50
+
+## Test Results
+
+**Platform**: Android (emulator-5554)  
+**Method**: Appium WebDriver + Device Console Logs  
+**Result**: ✅ **ALL TESTS PASSED**
+
+```
+=== SANDBOX: MainPage Constructor START ===
+=== SANDBOX: After InitializeComponent - Slider Value: 50, Stepper Value: 50 ===
+=== SANDBOX: ✅ VALIDATION PASSED ===
+
+Result: Value=50 (Expected: 50, Passed: True)  [All 3 order tests]
+
+Expected value to restore to 50: True  [Dynamic range test]
+```
+
+Full test logs available in `CustomAgentLogsTmp/Sandbox/android-device.log`
+
+## Related PRs
+
+- **Base PR**: #32939 - Fix Slider and Stepper property order independence
+- **Validates fix for issues**: #32903, #14472, #18910, #12243
+
+## Files Changed
+
+- `src/Controls/samples/Controls.Sample.Sandbox/MainPage.xaml` - Test UI with 4 test scenarios
+- `src/Controls/samples/Controls.Sample.Sandbox/MainPage.xaml.cs` - Test logic and validation
+
+## How to Test
+
+### Quick Test (Automated)
+```bash
+# Run Sandbox with Appium automation (requires Appium installed)
+pwsh .github/scripts/BuildAndRunSandbox.ps1 -Platform android
+```
+
+### Manual Test
+```bash
+# Build and deploy to Android
+dotnet build src/Controls/samples/Controls.Sample.Sandbox/Maui.Controls.Sample.Sandbox.csproj -f net10.0-android -t:Run
+
+# Verify in app:
+# 1. Test 1 section should show: "✅ All tests PASSED - Values correctly preserved!"
+# 2. Tap each programmatic test button - should show "✅ PASSED" for each
+# 3. Tap "Shrink Range" then "Expand Range" - should show "✅ Value restored to 50!"
+```
+
+### Verify Bug Reproduction (Optional)
+```bash
+# 1. Revert the fix
+git checkout main -- src/Controls/src/Core/Slider/Slider.cs src/Controls/src/Core/Stepper/Stepper.cs
+
+# 2. Rebuild - bug should appear (Value will be 10 instead of 50)
+dotnet build src/Controls/samples/Controls.Sample.Sandbox/Maui.Controls.Sample.Sandbox.csproj -f net10.0-android -t:Run
+
+# 3. Restore fix
+git checkout HEAD -- src/Controls/src/Core/Slider/Slider.cs src/Controls/src/Core/Stepper/Stepper.cs
+
+# 4. Rebuild - bug should be gone (Value correctly 50)
+dotnet build src/Controls/samples/Controls.Sample.Sandbox/Maui.Controls.Sample.Sandbox.csproj -f net10.0-android -t:Run
+```
+
+This proves the test scenario correctly reproduces the bug and validates the fix.
+
+## Review Documentation
+
+A comprehensive review document is available: `CustomAgentLogsTmp/PR32939-Review.md`
+
+Key findings:
+- ✅ Fix successfully resolves all test scenarios
+- ✅ No regressions observed
+- ✅ Minimal, surgical code changes
+- ✅ Comprehensive unit test coverage (98 tests)
+- ✅ Low risk, high community impact
+
+## Notes
+
+- Test scenario designed from issue #32903 reproduction steps
+- Includes console logging for debugging
+- UI elements have AutomationIds for Appium testing
+- Validation happens both programmatically (assertions) and visually (colored backgrounds)
+```
+
+---
+
+## Files Committed
+
+1. **src/Controls/samples/Controls.Sample.Sandbox/MainPage.xaml** (+75 lines)
+   - 4 test scenario sections with colored backgrounds
+   - AutomationIds on all interactive elements
+   - Clear labels showing expected vs actual behavior
+
+2. **src/Controls/samples/Controls.Sample.Sandbox/MainPage.xaml.cs** (+151 lines)
+   - ViewModel properties for XAML binding test
+   - Button event handlers for programmatic tests
+   - Console logging with `=== SANDBOX:` markers
+   - Validation logic with visual feedback
+
+---
+
+## Review Document
+
+**Location**: `CustomAgentLogsTmp/PR32939-Review.md`
+
+**Contents**:
+- Executive summary with approval recommendation
+- Technical analysis of the fix approach
+- Test validation results
+- Comparison with existing solutions
+- Risk assessment
+- Verification steps for reviewers
+
+**Key Recommendation**: ✅ **APPROVE AND MERGE**
+
+The fix is well-designed, comprehensively tested, and successfully validated. It solves a 3+ year old issue set with minimal risk.
+
+---
+
+## Next Steps
+
+1. **Create PR**: Visit https://github.com/kubaflo/maui/pull/new/sandbox-pr32939-validation
+2. **Copy PR description** from above
+3. **Set base branch**: `fix/slider-stepper-property-order-independence`
+4. **Label**: `area-controls-slider`, `area-controls-stepper`, `t/test`
+5. **Link to PR #32939** in the description
+
+---
+
+## Additional Files (Not Committed - In .gitignore)
+
+Available in `CustomAgentLogsTmp/Sandbox/`:
+- `RunWithAppiumTest.cs` - Appium test automation script
+- `android-device.log` - Device console logs showing all tests passing
+- `appium.log` - Appium server logs
+- `appium-test-output.log` - Appium test execution results
+
+These files are preserved locally for reference but excluded from git per .gitignore.
+
+---
+
+**Created by**: GitHub Copilot CLI (Sandbox Testing Agent)  
+**Date**: December 1, 2025  
+**Purpose**: Validate PR #32939 fix for Slider/Stepper property order independence