[Bug] CJK PDFs render blank and index empty: PDF.js CMap/font assets are not bundled #130

Symptom

CJK PDFs (Chinese / Japanese / Korean) fail in two places at once:

• Reader: the canvas has no glyphs for CJK runs; the text layer is missing the same text.
• Ingestion: PdfLoader.getTextContent() silently drops every CJK run, so chunks contain only the Latin/ASCII text. Anything the model could retrieve from that document is therefore wrong or empty — this is a plausible part of why notebook chat "does not retrieve or cite indexed knowledge" for CJK sources.

The only signal is a warning, not an exception:

Warning: loadFont - translateFont failed:
"UnknownErrorException: Ensure that the `cMapUrl` API parameter is provided."
Warning: Error during font loading:
Ensure that the `cMapUrl` API parameter is provided.

Because it is a warning, both paths "succeed" with missing text.

Root cause

PDF.js treats predefined CMaps, standard fonts and the wasm image decoders as external assets fetched by filename (${cMapUrl}${name}.bcmap). KnowNote never passed any of the three to getDocument:

• PdfLoader.ts — getDocument({ data, password })
• PdfSourceReader.tsx — getDocument({ data })

pdfjs-dist ships the files (cmaps/, standard_fonts/, wasm/), but nothing references them.

Reproduced on main with noembed-jis7.pdf (non-embedded Japanese font):

Scope

1. Bundle pdfjs-dist/{cmaps,standard_fonts,wasm} as real files (electron-builder extraResources → resources/pdfjs/, outside app.asar).
2. Pass cMapUrl + cMapPacked: true to both getDocument call sites.
3. Pass standardFontDataUrl and wasmUrl too — PDF.js exposes all three as one contract.
4. Renderer reads them through a dedicated knownote-asset:// protocol (the renderer must not receive filesystem paths, same rule as knownote-doc://). Main reads them as filesystem paths.
5. CSP: allow the scheme in connect-src; add 'wasm-unsafe-eval' for wasm compilation. The scripting boundary from security(pdf): remediate GHSA-hq66-cqwq-w95j before v1.4 (pdfjs-dist 5.7.284 in affected range) #121 is unaffected — that forbids JS eval/inline script, and script-src still has no 'unsafe-eval'.
6. Verify the packaged layout, not just npm run dev.

Acceptance

Renderer

• the same CJK PDF renders CJK on the canvas
• no cMapUrl / font-loading warnings in the console
• the text layer is selectable and shows CJK

Ingestion / retrieval

• getTextContent() on the same PDF returns correct CJK
• document blocks and chunks contain correct CJK
• a distinctive CJK sentence from the document is retrieved by Retriever

Packaging

• npm run build:unpack ships resources/pdfjs/{cmaps,standard_fonts,wasm}
• npm run smoke:packaged passes on the packaged app

Related

• Found by the v1.4 release QA in [Test] v1.4 release QA: PDF reader end-to-end + IA smoke in both themes #125.
• Blocks [Epic] v1.4 — Trusted Research Loop: source provenance end to end #82 (Trusted Research Loop) for any CJK source.
• Independent of the blank-canvas crash fixed in fix(reader): render the PDF reader with the pdfjs legacy build #129; a correct renderer still needs this.