Adds 3 drain_token lemmas to en_core_math_v1 closing 2 of 3 remaining
lexicon_entry refusals from the prior wave:
- path (case 0049, new lemma)
- journey (case 0049 follow-on after path resolved)
- sees → alias of existing "see" lemma (case 0040)
The third remaining lexicon_entry refusal (case 0001, '+') is
deliberately NOT closed: '+' is an arithmetic operator literal, not a
lexical token. Adding it as drain_token would silently drop arithmetic
content from problems like "5 + 3 apples", a wrong=0 hazard. Documented
in the PR body and audit artifact.
Refusal taxonomy shift:
- unknown_word: 5 → 3 (-2)
- unresolved_pronoun: 3 → 4 (+1) — case 0049's pronoun barrier surfaced
- incomplete_operation: 20 → 21 (+1) — case 0049's quantity gap surfaced
Hard invariants:
- wrong == 0 (admitted=0, verified)
- case 0050 hazard pinned (refused at sentence_index=0)
- manifest checksum unchanged (per-category source file edit)
- no teaching-store mutation; no reader runtime change