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.

view.js

@@ -121,6 +121,14 @@ export const makeBook = async (file, options = {}) => {
             const { makeFB2 } = await import('./fb2.js')
             book = await makeFB2(file)
         }
+        else if (await (await import('./pdb.js')).isPDB(file)) {
+            const { makePalmDocBook } = await import('./pdb.js')
+            book = await makePalmDocBook(file)
+        }
+        else if (await (await import('./rtf.js')).isRTF(file)) {
+            const { makeRTFBook } = await import('./rtf.js')
+            book = await makeRTFBook(file)
+        }
         else {
             const { isText, makeTextBook } = await import('./text.js')
             if (isText(file)) book = await makeTextBook(file)