Daily Test Coverage Improver: XElementExtensions tests for Xml.Core module

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Summary

• Adds comprehensive test coverage for XElementExtensions in FSharp.Data.Xml.Core
• Implements 14 test cases covering XElement.Request and RequestAsync methods
• Achieves 100% coverage for XElementExtensions (previously 0%)

Coverage Impact

• FSharp.Data.Xml.Core: 0% → 5.3% (+5.3 percentage points)
• FSharp.Data.XElementExtensions: 0% → 100% (+100 percentage points)
• Total Project Coverage: 55.7% → 56.4% (+0.7 percentage points)
• Lines Covered: +34 lines (2898 → 2932)
• Methods Covered: +3 methods (557 → 560)

Test Coverage Details

Tests comprehensively cover:

HTTP Request Methods

• ✅ Default POST method behavior
• ✅ Custom HTTP method support (PUT)
• ✅ Request/RequestAsync method parity

Header Management

• ✅ Default User-Agent header injection
• ✅ Custom header support
• ✅ User-Agent preservation when provided
• ✅ Content-Type XML header inclusion

XML Serialization

• ✅ Simple XML element serialization
• ✅ Complex nested XML structures
• ✅ XML namespace handling
• ✅ Compact serialization (SaveOptions.DisableFormatting)

Technical Implementation

• ✅ Uses local ASP.NET Core test server (similar to existing HTTP tests)
• ✅ Proper HttpResponseBody pattern matching for Text/Binary responses
• ✅ Async operation testing with Async.RunSynchronously
• ✅ All 14 tests pass consistently

Security Compliance

• No external network dependencies (uses localhost test server)
• No hardcoded credentials or sensitive data
• Follows existing test patterns for HTTP mocking
• Safe for automated CI/CD execution

🤖 Generated with Claude Code