Validate-Preload-Async-Defer-Scripts:
- Add missing fetchpriority="low" to <link rel=preload> tag in Solution 1
  This was a correctness bug - preload without fetchpriority="low" still
  escalates network priority even if script tag has fetchpriority="low"

Prefetch-Resource-Validation (comprehensive improvements):

Performance optimizations:
- Pre-normalize all URLs once into a Map (eliminates O(N×M) URL parsing)
- Use pre-built URL map for all matching operations
- Remove redundant URL parsing in nested loops
- Performance improvement: ~6000 URL objects → ~200 for typical cases

New validations:
- Detect invalid 'as' attribute values (typos like as="scriptt")
- Detect duplicate prefetch hints (same URL prefetched multiple times)
- Warn about large scripts (>1MB threshold, was missing)
- Validate 'as' attribute against list of valid values

Improved logic:
- Better cache detection: distinguish "cached" vs "unknown (CORS)"
  Handles case where CORS blocks timing info (both sizes === 0)
- Fixed inappropriateTypes to check scripts and provide detailed reasons
- Optimized isCurrentPageResource check to use pre-built map
- Added seenUrls Set to track duplicates

Code quality:
- Added validAsValues Set with all valid 'as' attribute values
- Added THRESHOLDS.largeScriptSize (1MB) for script-specific checks
- Better error messages with specific size/reason for inappropriateness
- Comments explaining CORS edge cases and validation logic

Documentation updates:
- Added "Invalid as", "Duplicate prefetch" to issue categories table
- Updated "Inappropriate type" description to mention scripts
- Cache status can now show "unknown (CORS)" in output

Addresses issues from comprehensive code review:
- URL matching performance (#8, #9 from analysis)
- Invalid 'as' validation (#7)
- Duplicate detection (#14)
- Large script detection (#4)
- Cache detection for CORS (#3)
- Current page detection optimization (#6)

add layout shift script

Validate-Preload-Async-Defer-Scripts:
- Add missing fetchpriority="low" to <link rel=preload> tag in Solution 1
  This was a correctness bug - preload without fetchpriority="low" still
  escalates network priority even if script tag has fetchpriority="low"

Prefetch-Resource-Validation (comprehensive improvements):

Performance optimizations:
- Pre-normalize all URLs once into a Map (eliminates O(N×M) URL parsing)
- Use pre-built URL map for all matching operations
- Remove redundant URL parsing in nested loops
- Performance improvement: ~6000 URL objects → ~200 for typical cases

New validations:
- Detect invalid 'as' attribute values (typos like as="scriptt")
- Detect duplicate prefetch hints (same URL prefetched multiple times)
- Warn about large scripts (>1MB threshold, was missing)
- Validate 'as' attribute against list of valid values

Improved logic:
- Better cache detection: distinguish "cached" vs "unknown (CORS)"
  Handles case where CORS blocks timing info (both sizes === 0)
- Fixed inappropriateTypes to check scripts and provide detailed reasons
- Optimized isCurrentPageResource check to use pre-built map
- Added seenUrls Set to track duplicates

Code quality:
- Added validAsValues Set with all valid 'as' attribute values
- Added THRESHOLDS.largeScriptSize (1MB) for script-specific checks
- Better error messages with specific size/reason for inappropriateness
- Comments explaining CORS edge cases and validation logic

Documentation updates:
- Added "Invalid as", "Duplicate prefetch" to issue categories table
- Updated "Inappropriate type" description to mention scripts
- Cache status can now show "unknown (CORS)" in output

Addresses issues from comprehensive code review:
- URL matching performance (#8, #9 from analysis)
- Invalid 'as' validation (#7)
- Duplicate detection (#14)
- Large script detection (#4)
- Cache detection for CORS (#3)
- Current page detection optimization (#6)