Drop substantivized-adjective false nouns via manual_reject.txt

OpenCorpora/libmorph hand a noun reading to Stage 2 above the РАН note, so
substantivized-adjective false nouns a dictionary misreads (нёбный, акцизный,
велярный, …) reached scrabble.txt with no veto path — the earlier abbreviation
filter only carved out Abbr+Fixd.

ru_stage2.py now subtracts sources/scrabble_ru/manual_reject.txt last, after
every admission path (OC seed / libmorph / note / manual_confirm / variant),
mirroring manual_confirm.txt. The list seeds 62 hand-reviewed words — 43 pure
adjectives plus 19 marginal (slang/archaic/jargon) substantivizations; genuine
substantivized nouns (больной, знакомый, учёный, участковый, …) stay.

scrabble.txt -62 (83206->83144); erudit.txt re-folded -62. The DAWGs are
gitignored and rebuild from these lists in CI.

tools/README.md

@@ -33,6 +33,7 @@ process's memory (dump it with `--dump`, query it with `--trace WORD`).
 | `orfo_dict_2025.txt` | ✓ | the pdftotext output — the parsed source of truth (the PDF binary is not needed to rebuild). |
 | `all.txt` | ✓ | Stage 1 base: every clean Cyrillic headword/variant; a plural headword with a singular is replaced by that singular. |
 | `manual_confirm.txt` | ✓ | hand-reviewed nouns from the undefined tail; the brain merges them into the result. |
+| `manual_reject.txt` | ✓ | hand-vetoed false nouns (substantivized adjectives a dictionary misreads as nouns, e.g. нёбный); subtracted from the result last. |
 | `scrabble.txt` | ✓ | **Stage 2 result**: common nouns, nominative singular (+ pluralia tantum), length 2–15 — the working dictionary. |
 | `undefined.txt` | — | the ambiguous tail; kept in memory, written only with `--dump`. |
 
@@ -127,6 +128,10 @@ Each Stage-1 word (length 2–15) is routed by three sources, most authoritative
    травмпункт`, `регги и реггей`) and one is already a confirmed noun, the other is moved
    from review/undefined into the result as well, propagated transitively through chains.
    The plural-form variants the dictionaries already resolve never reach this step.
+5. **Manual overrides**: `manual_confirm.txt` adds maintainer-approved nouns from the
+   undefined tail (before variant rescue, so they can anchor it); `manual_reject.txt` is
+   subtracted **last**, removing false nouns a dictionary misreads — substantivized
+   adjectives with no nominal use (`нёбный`, `акцизный`, …) — overriding every path above.
 
 The nominative singular always comes from the dictionary that recognised the word, or from
 the orthographic `ед.` note — never from a predictor guess (libmorph and the predictor