Tighten target detection edge case handling

[oleksiikolomiietssnapp]

Review and strengthen the Package.swift parsing and folder pattern matching logic for edge cases.

Current Strengths

• Good fallback mechanism: Package.swift → folder patterns → project name
• Intelligent longest-path matching for nested structures
• Handles test filtering well

Improvements Needed

Following patterns from SwiftPackageScripts:

1. Explicit Validation

   • Validate simulator/path availability before processing (like their get_latest_simulator)
   • Check that extracted target names are valid (not empty, not test-like)
   • Return clear error codes on validation failure

2. Edge Cases to Handle

   • Deeply nested directory structures (>3 levels)
   • Symlinks in source paths
   • Non-standard Package.swift formats
   • Unicode characters in target names
   • Targets with similar path prefixes (ensure longest match wins consistently)

3. Fallback Robustness

   • Better logging of which detection method succeeded (currently done, but could be clearer)
   • Explicit error when no valid targets detected
   • Handle malformed jq output gracefully

4. Test Coverage

   • Document expected patterns for file paths
   • Add examples of edge cases handled