fix: handle nested types and constructor parameters in UID filter matching

[thomhurst]

The CouldMatchUidFilter method was failing to match tests when using
VS Test Explorer because:

1. For nested types (e.g., Outer+Inner), Type.Name only returns the
   innermost class name, but UIDs contain the full path with '+' separators

2. For classes with constructor parameters, UIDs contain '(' after the
   class name (e.g., MyClass(String).0.0.Method), but the code only
   checked for '.' or '<'

This fix:

• Adds BuildClassNameForMatching() to construct the full nested type
  hierarchy matching TestIdentifierService.WriteTypeNameWithGenerics
• Validates the character after the class name prefix is a valid
  boundary: '.', '<', or '('
• Maintains protection against substring matching (ABCV vs ABCVC)

Fixes #4656 (follow-up issue after PR #4659)

https://claude.ai/code/session_016KqnWq2pDNM7sDLSn6LvRe

[claude]

Code Review - Two Issues Found

1. Allocation in Hot Path (CLAUDE.md Violation)

The new BuildClassNameForMatching() method allocates a List in test discovery (hot path #1). Lines 283-306 allocate List and use string.Join().

CLAUDE.md Rule: Performance First - Minimize allocations in hot paths (test discovery, execution)

See:

TUnit/CLAUDE.md

Line 15 in fe8aa8f

4. **Performance First** - Minimize allocations in hot paths. Cache reflection. Use `ValueTask` for potentially-sync operations.

The established pattern in TestIdentifierService.WriteTypeNameWithGenerics (lines 118-184) uses ValueListBuilder for the same operation.

Suggested fix: Use ValueListBuilder instead of List to match the established pattern.

---

2. Critical Bug: Nested Generic Types Not Handled

BuildClassNameForMatching() does not include generic type arguments for outer types in nested hierarchies. This causes incorrect filtering.

Example for Outer.Inner:

• TestIdentifierService generates: MyNamespace.Outer<System.Int32>+Inner.0.0.Method
• BuildClassNameForMatching generates: MyNamespace.Outer+Inner
• Result: StartsWith check fails

Root cause: Lines 293-300 strip the backtick suffix but dont append generic type arguments like TestIdentifierService does (lines 143-155).

This breaks TUnits dual-mode architecture by creating inconsistency between test identification and filtering.

Suggested fix: Include generic type arguments for ALL types in the hierarchy, matching the format in TestIdentifierService.WriteTypeNameWithGenerics lines 143-155.

[thomhurst]

Code Review

No issues found. Checked for bugs and CLAUDE.md compliance.