docs(wiki): document pikpak-kotlin 2.0.0 Describe the file cache, durable downloads, foreground idle rule, lease lifecycle, and outstanding rebuild risk. Update the installation version and migration history for 2.0.0.
Correct the storage cost of an instant upload and add free-account facts
Document pikpak-kotlin 1.0.0 Getting started, best practices, playback, magnets and instant create, drive operations, uploads and offline tasks, errors and retries, architecture with the 2026-09-27 design review, dated measurements, history of removed designs, and the development and release checklist. Replaces the README's manual, DESIGN-NOTES.md and the DeepWiki page. Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_0119qFo3dRwvZArC7NQHigca