feat(rtff-pdb): RTF and PalmDOC plain-text support (v0.5.0)

rtf.js: a minimal single-pass RTF tokenizer extracting document text
with paragraph structure — groups, control words with signed params,
\\'hh Windows-1252 escapes, \\uN unicode with \\ucN fallback skipping,
known text destinations skipped whole (fonttbl/colortbl/stylesheet/
info/headers/pict/field/...), spec-required ignoring of unknown words.
Format runs are intentionally not converted; RTF is read as styled
text like .txt.

pdb.js: the TEXt/REAd PalmDOC container (PalmDOC, TealDoc) — the PDB
record reader and LZ77 decompressor are shared from mobi.js (both
exported; upstream already carried the TODO for this path). Records
decode as Windows-1252 and feed the plain-text pipeline (paragraph
split, line join, ~150KB sectioning, Part N TOC).

makeBook dispatch: content-based (TEXtREAd magic at offset 60;
'{\\rtf' magic), after MOBI and before the text branch.

Tests: node harness covering store + compressed PalmDOC, RTF paragraphs
/escapes/unicode/hex/destination-skipping, makeBook routing; txt/docx
regression suites pass.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "foliate-js",
-  "version": "0.3.1",
+  "version": "0.5.0",
   "description": "Render e-books in the browser",
   "repository": {
     "type": "git",