* lazy PDF loading w/ PDFDataRangeTransport
* lint
* feat: lazy PDF loading via range transport + eager background preloading
Replace full-file download with PDFDataRangeTransport so PDF.js fetches
byte ranges on demand. First page renders immediately; remaining pages
load in background for search.
**Range transport (server + client)**
- server.ts: add read_pdf_bytes tool returning base64 chunks with offset
- mcp-app.ts: AppRangeTransport feeds PDF.js via fetchRange/fetchChunk
with parallel sub-requests for large ranges, Promise-based dedup of
concurrent requests, and a persistent range cache
**Background preloader**
- Sequential page 1→N text extraction, pauses during interactive
navigation (preloadPaused flag set in goToPage, cleared in renderPage)
- Debounced live search refresh (500ms) as pages load
- Search UI shows '(loading…)' suffix until all pages processed
**Loading indicators**
- SVG pie in toolbar: fills as pages load, fades on completion,
turns red on errors with tooltip listing failed pages
- Debounced page-loading overlay (150ms) for uncached page navigation
**Cleanup**
- Remove old full-file chunked download and progress bar
- Remove extractAllPageText (replaced by preloader)
- Remove verbose debug logs (Coverage, RangeReq, cache hit)