refactor(reader): remove vendored pdfjs files from git, drop CJK cmaps

Remove 185 binary files (169 CMaps + 16 standard fonts) from git
tracking. These are build artifacts copied from
node_modules/@bookhoard/foliate-js at build time and should not be
version-controlled.

Changes:
- Remove web/static/vendor/pdfjs/ from git (169 cmap files + 16
  standard font files)
- Add web/static/vendor/ to .gitignore
- Drop CJK cmap copying from build scripts — the app is English-only
  and CJK support can be re-added later if needed (saves ~1.7MB in
  the container image)
- Update all three build scripts (build:ts, build:ts:dev,
  build:ts:watch) to copy only standard_fonts/ from node_modules
- Remove cMapUrl from reader.ts PDF config since we no longer ship
  cmaps
- Keep standardFontDataUrl pointing to the build-copied fonts which
  are needed for PDFs with non-embedded standard fonts (Helvetica,
  Times, Courier, etc.)

web/src/reader/reader.ts

@@ -438,7 +438,6 @@ document.addEventListener("alpine:init", () => {
       const file = new File([blob], fileName, { type: blob.type });
       await this.view.open(file, {
         pdf: {
-          cMapUrl: "/static/vendor/pdfjs/cmaps/",
           standardFontDataUrl: "/static/vendor/pdfjs/standard_fonts/",
         },
       });