feat(youtube): support podcasts tab and recommended podcasts kiosk

[Priveetee]

Refs InfinityLoop1308/PipePipe#577

Commits

• Priveetee@c9d1f446
• Priveetee@6ac89c67
• Priveetee@9f69bb2b

Summary

• Add YouTube channel podcasts tab extraction support (/podcasts mapping + URL normalization for query/fragment/trailing slash variants).
• Add lockup parsing paths used by podcast payloads (lockupViewModel for podcast/video content types), including nested rich-item shapes.
• Add Recommended Podcasts kiosk support (/podcasts, /podcasts/videos) and parse feed via browseId=FEpodcasts_destination with params qgcCCAM=.
• Cap podcast recommendation extraction to 40 items for smoother client scrolling.

Why

• #577 requires podcast tab support on channel pages and reliable extraction for payload variants that currently lead to empty/incomplete results.
• Client podcast UX also needs a podcast recommendations source instead of generic related items in podcast context.

Tests

• Added/updated focused extractor tests:
  • channel podcast tab link handler mapping
  • channel podcast tab parsing
  • lockup parsing paths for podcast payloads
  • trending link handler podcasts mapping
  • service kiosk availability
• Build validation:
  • JAVA_HOME=/usr/lib/jvm/java-11-openjdk ./gradlew :extractor:compileJava -x checkstyleMain ✅

Notes

• Commits are intentionally split and each stays under 290 insertions.
• In this fork state, full :extractor:test compile remains blocked by pre-existing unrelated test-suite issues; focused tests and integration/device validation were run for this feature.