Fix infinite loop in hierarchical term generation for brands

[layoutd]

Summary

Fixes infinite loop issue in Term::batch_hierarchical() that caused test_batch_validation_max_size to hang indefinitely.

Problem

• The brand feature uses deviceManufacturer() which has limited unique values
• When generating multiple brand terms, duplicate names cause term_exists errors
• The retry logic (--$i) would loop forever without any exit condition
• Test generating 100 products would hang trying to create 5-10 unique brands

Solution

Added max retry limit to Term::batch_hierarchical():

• Tracks retry attempts with $retry_count
• Sets max retries to $amount * 10 (reasonable for duplicates)
• Breaks loop when max retries exceeded instead of hanging
• Maintains existing duplicate handling behavior

Test Results

• ✅ test_batch_validation_max_size: Now passes in ~2.5s (was hanging forever)
• ✅ All GeneratorTest: 5/5 tests pass
• ✅ Full test suite: 103 tests, 235 assertions pass in ~10.5s

Files Changed

• includes/Generator/Term.php: Added retry limit logic in batch_hierarchical()
• includes/Generator/Product.php: Ensured brands use max-depth => 1 to avoid hierarchy complexity

[layoutd]

Closing this PR as we've addressed the issue directly in the base branch.

Instead of adding retry limits to handle deviceManufacturer()'s limited unique values (only 6), we switched to using company() which provides hundreds of unique company names. This completely avoids the duplicate term/infinite loop issue without needing additional safety logic.

The fix has been incorporated into fix/pr-174-review-feedback branch.