Update the badge to point to maui-pr-public

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Co-authored-by: Copilot <198982749+Copilot@users.noreply.github.com>
Co-authored-by: rmarinho <1235097+rmarinho@users.noreply.github.com>

### Description of Change

Now the correct links

<!-- Please let the below note in for people that find this PR -->
> [!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 improves the `verify-tests-fail-without-fix` skill by fixing
fork repository detection, improving error handling, and making full
verification the recommended/default behavior.

## Changes

### 1. **Added `git fetch origin` for Accurate Diffs**
- Fetches the base branch from origin before computing git diff
- Ensures accurate fix file detection even in fork repositories
- Prevents false negatives when base branch is stale locally

### 2. **Improved Verification Mode Behavior**
- **Made full verification the primary/default mode** - tests must FAIL
without fix and PASS with fix
- **Added `-RequireFullVerification` parameter** - prevents silent
fallback to verify-only mode
- **Improved error handling** - script now warns/errors if no fix files
detected (instead of silently switching modes)
- **Verify-only mode still available** - runs when no fix files detected
AND `-RequireFullVerification` not set
- **Clearer expectations** - user explicitly controls whether
verify-only fallback is allowed

### 3. **Improved Documentation**
- Updated SKILL.md to reflect improved mode behavior
- Clarified requirements (fix files + test files for full verification)
- Updated mode selection table to show both modes clearly
- Added troubleshooting guidance for "no fix files detected" scenario

### 4. **Better Error Handling**
- Script exits early with actionable error if no fix files found AND
`-RequireFullVerification` set
- Provides explicit solutions (use `-FixFiles` or `-BaseBranch`
explicitly)
- Reduced ambiguity - user knows exactly what mode is running

## Why These Changes?

### Problem 1: Fork Repository Detection
When working in a fork, the base branch might not be up-to-date locally,
causing `git diff` to produce inaccurate results. This led to:
- Missing fix files in the diff
- False "only test files" mode activation
- Incorrect verification results

**Solution**: Always fetch the base branch from origin before computing
diff.

### Problem 2: Confusing Auto-Detection
The previous auto-detection system was unclear:
- Silent fallback to "verify failure only" when no fix files detected
- Users didn't know which mode was running
- Made debugging harder

**Solution**: 
- Add `-RequireFullVerification` parameter to make expectations explicit
- Error immediately if user expects full verification but no fix files
found
- Maintain verify-only mode for legitimate test-first workflows

### Problem 3: Silent Failures
When no fix files were detected (due to stale base branch or wrong base
detection), the script would silently fall back to "verify failure only"
mode, which wasn't the intended behavior.

**Solution**: Fail fast with clear error message and troubleshooting
steps when `-RequireFullVerification` is set.

## Testing

Verified the changes work correctly with:
- ✅ Fork repositories (fetch ensures accurate base branch)
- ✅ PRs with fix files + test files (full verification runs)
- ✅ Clear error when no fix files detected with
`-RequireFullVerification`
- ✅ Verify-only mode still works when appropriate (without the flag)
- ✅ `-RequireFullVerification` parameter enforces strict mode

## Example Usage

```bash
# Recommended for PR validation - ensures full verification
pwsh .github/skills/verify-tests-fail-without-fix/scripts/verify-tests-fail.ps1 -Platform android -RequireFullVerification

# With explicit test filter
pwsh .github/skills/verify-tests-fail-without-fix/scripts/verify-tests-fail.ps1 -Platform ios -TestFilter "Issue33356" -RequireFullVerification

# Override fix files or base branch if auto-detection fails
pwsh .github/skills/verify-tests-fail-without-fix/scripts/verify-tests-fail.ps1 -Platform android -FixFiles @("src/Core/File.cs") -BaseBranch "main"

# Test-first workflow (verify tests fail before writing fix)
pwsh .github/skills/verify-tests-fail-without-fix/scripts/verify-tests-fail.ps1 -Platform ios
```

## Breaking Changes

⚠️ **Behavior Change**: The skill now requires explicit intent when fix
files are not detected:
- **Without `-RequireFullVerification`**: Falls back to verify-only mode
(tests only need to FAIL)
- **With `-RequireFullVerification`**: Errors immediately if no fix
files found

**Recommended usage**: Always use `-RequireFullVerification` when
validating PRs to ensure full verification (tests FAIL without fix, PASS
with fix).

**Migration**: Update any automated scripts that call this skill to add
`-RequireFullVerification` for PR validation workflows.

## Related

- Part of improving PR verification workflows
- Complements the `pr` custom agent for better PR validation
- Ensures consistent behavior across fork and non-fork repositories
```

---

## Key Changes from Current Description

### Change 1: Section 2 Title and Content

**Current (inaccurate):**
```markdown
### 2. **Simplified Verification Mode**
- **Removed** "verify failure only" mode (when only test files exist)
```

**Corrected:**
```markdown
### 2. **Improved Verification Mode Behavior**
- **Made full verification the primary/default mode** - tests must FAIL
without fix and PASS with fix
- **Verify-only mode still available** - runs when no fix files detected
AND `-RequireFullVerification` not set
```

### Change 2: Breaking Changes Section

**Current (inaccurate):**
```markdown
⚠️ **Behavior Change**: The skill no longer supports "verify failure
only" mode.
```

**Corrected:**
```markdown
⚠️ **Behavior Change**: The skill now requires explicit intent when fix
files are not detected:
- **Without `-RequireFullVerification`**: Falls back to verify-only mode
(tests only need to FAIL)
- **With `-RequireFullVerification`**: Errors immediately if no fix
files found
```

### Change 3: Added Test-First Workflow Example

**Added:**
```bash
# Test-first workflow (verify tests fail before writing fix)
pwsh
.github/skills/verify-tests-fail-without-fix/scripts/verify-tests-fail.ps1
-Platform ios
```

This clarifies that verify-only mode is still useful for legitimate workflows.

---

## Why This Correction Matters

**Code Reality**: The implementation shows verify-only mode still exists at lines 173-193:
```powershell
if ($DetectedFixFiles.Count -eq 0) {
Write-Host "║ VERIFY FAILURE ONLY MODE ║"
    # ... mode implementation
}
```

**Impact of Inaccuracy**: 
- Future maintainers reading "removed" will be confused when they see the mode in code
- Users might think they can't use verify-only mode for test-first workflows
- Documentation doesn't match reality

**Correction Approach**:
- Acknowledge mode still exists
- Explain it's no longer the silent fallback (key improvement)
- Show it's still useful for test-first development
- Emphasize full verification is now recommended/default

---

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Co-authored-by: Shane Neuville <shneuvil@microsoft.com>