Reading Partner v0.2.0
Reading-engine layer refactor: an EmbedPDF engine adapter now lands on main. - EmbedPDF engine adapter for PDF, experimental and behind the VITE_ENGINE=embedpdf flag; the default engine remains zotero/reader. - Performance fixes: tile-based zoom rendering, engine subtree isolation to contain popup re-renders, and load-time pass (engine singleton, trimmed render buffer). - New pitfall docs and EmbedPDF replacement research under docs/.