Merge pull request #2 from cruisediary/feature/wwdc17-session-coverage

docs: update README with WWDC17–25 coverage tree and session counts

docs: update CONTRIBUTING.md with WWDC17 year-specific notes

feat: add WWDC17 session rows to INDEX.md

feat: add WWDC17 SiriKit and networking session files

feat: add WWDC17 new frameworks session files (NFC, MapKit, MusicKit, GCD, Metal 2)

feat: add WWDC17 iOS 11 UI and Drag & Drop session files

feat: add WWDC17 Swift 4 and dev tools session files

feat: add WWDC17 ML/AI session files (ARKit, Core ML, Vision)

chore: extend audit.py to validate 2017 session files

docs: add CONTRIBUTING.md and .github PR/issue templates

docs: update README with correct repo URL and add MIT license

chore: add .gitignore; remove local Claude settings from tracking

feat: raise reliability to A — session IDs, shape compliance, audit script

fix: support 3-digit session IDs in router (WWDC18/19)