This PR standardizes how size-related properties are handled across all
GitHub classes to ensure consistency in storage format and display
formatting.

## Changes Made

### 1. GitHubRepository
- **Property**: Updated `Size` property to store bytes instead of
kilobytes
- **Storage**: Convert API values using `$Object.size * 1KB` and
`$Object.diskUsage * 1KB`
- **Display**: Updated format file to use
`[GitHubFormatter]::FormatFileSize($_.Size)`
- **Documentation**: Updated comments to reflect "in bytes" instead of
"in kilobytes"

### 2. GitHubOrganization
- **Property**: Renamed `DiskUsage` property to `Size` for consistency
- **Storage**: Convert API values using `$Object.disk_usage * 1KB` 
- **Compatibility**: Added `DiskUsage` alias property for backward
compatibility
- **Documentation**: Updated comments to reflect "size of organization's
repositories, in bytes"

### 3. GitHubArtifact
- **Display**: Updated format file to use
`[GitHubFormatter]::FormatFileSize($_.Size)` instead of custom
formatting
- **Property**: Already correctly stores bytes and uses "Size" property
name
- **Label**: Updated table header from "Size (KB)" to "Size" for cleaner
display

### 4. Format File Updates
All affected format files now use the standardized
`[GitHubFormatter]::FormatFileSize()` method instead of custom size
calculations, ensuring consistent human-readable formatting across all
size displays.

### 5. Comprehensive Test Coverage
- **GitHubFormatter.Tests.ps1**: New test file validating unit
conversion logic (KB→bytes), type boundaries, and format patterns
- **Enhanced Integration Tests**: Added size property validation tests
to Repositories.Tests.ps1, Organizations.Tests.ps1, and
Artifacts.Tests.ps1
- **Unit Verification**: Tests confirm all size properties store values
in bytes and use expected denominations
- **Compatibility Testing**: Validates DiskUsage alias functionality and
backward compatibility

## Verification

The changes maintain backward compatibility and existing functionality:
- Size conversions work correctly: 108 KB → 110,592 bytes → "108.00 KB"
display
- Tests continue to pass (they only verify `Size > 0`)
- New tests verify correct unit storage and formatting behavior
- GitHubReleaseAsset was already implemented correctly as the reference
standard

## Example Impact

Before:
```powershell
# GitHubRepository.Size = 108 (kilobytes)
# Display: "0.11 MB" (custom calculation)

# GitHubOrganization.DiskUsage = 10000 (kilobytes)  
# Display: Not shown in table format
```

After:
```powershell
# GitHubRepository.Size = 110592 (bytes)
# Display: "108.00 KB" (standardized formatter)

# GitHubOrganization.Size = 10240000 (bytes)
# GitHubOrganization.DiskUsage -> Size (alias for compatibility)
# Display: "9.77 MB" (standardized formatter)
```

Fixes #478.

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---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: MariusStorhaug <17722253+MariusStorhaug@users.noreply.github.com>
Co-authored-by: Marius Storhaug <marstor@hotmail.com>

…-GitHubSecret` and `Remove-GitHubVariable` (#499)

This pull request improves the handling and testing of secret and
variable removal in the GitHub module. The main focus is on making the
removal functions (`Remove-GitHubSecret`, `Remove-GitHubVariable`) more
robust and scope-aware, and on expanding the test coverage to ensure
correct behavior across different usage patterns and scopes.

- Fixes #388

Key changes include:

### Functional improvements to removal logic

* Updated `Remove-GitHubSecret.ps1` and `Remove-GitHubVariable.ps1` to
dispatch removal actions based on the `Scope` property of each item,
ensuring the correct removal function is called for environment,
repository, or organization scopes, and providing clear error handling
for unsupported scopes.

### Documentation and class property clarifications

* Improved property descriptions in `GitHubSecret.ps1` and
`GitHubVariable.ps1` to clarify that properties refer to where the
secret or variable is stored, enhancing code readability and
maintainability.

### Expanded and improved test coverage

* Refactored and expanded tests in `Secrets.Tests.ps1` and
`Variables.Tests.ps1` to:
- Add separate tests for pipeline-based removal using both direct
pipeline and variable assignment approaches.
- Ensure secrets and variables are created and removed correctly in all
supported scopes.
- Add logging and verification steps to improve test clarity and
debugging.

These changes make the module's behavior more predictable and easier to
test, especially when handling secrets and variables in different scopes
and using pipeline operations.

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: MariusStorhaug <17722253+MariusStorhaug@users.noreply.github.com>
Co-authored-by: Marius Storhaug <marstor@hotmail.com>