Shared lexicon (c): one corporate-suffix token base + composer, preserving the four vocabularies' memberships

[s-annam]

Part (c) of #653. Behaviour-preserving consolidation with one deliberate distinction to protect.

Problem

Corporate-suffix vocabulary (Inc, LLC, Ltd, GmbH, …) exists as four separate sets across the parser. The #641 fix — "the captured token carries a trailing period" — had to be diagnosed and applied per copy, which is the tell.

Implementation plan

1. Create one token base under src/lib/heuristics/extract/ holding the suffix tokens as data.
2. Add a composer that generates each of the four vocabularies from it, with an allowTrailingDot option so the [parser] Pass B single-token city rule cleaves a company whose last word precedes a state tail (Palo Alto Networks, CA) #641 behaviour is expressed once and applied where it belongs.
3. Repoint the four sites at the composer.

Constraint — do not collapse the sets

Membership stays per-set human judgement. The tail-deferral vocabulary at src/lib/heuristics/extract/experience-disambiguate.ts:188-199 is deliberately broader than COMPANY_SUFFIX_RE: it includes tokens like Media and Partners. Adding those to the strict set would flip looksLikeTitle false on a real title such as "Media Director".

So this issue shares the token base and the composition mechanics, not the memberships. Each generated set keeps its own explicit token list and a docblock saying what it is for and why it differs.

Acceptance criteria

• One token base + composer under extract/; the four vocabularies are generated from it.
• allowTrailingDot (the [parser] Pass B single-token city rule cleaves a company whose last word precedes a state tail (Palo Alto Networks, CA) #641 behaviour) is implemented once in the composer.
• Each generated set retains its own membership and a docblock explaining the divergence from the strict set.
• A test pins that experience-disambiguate.ts's broader set still contains Media/Partners and that the strict set does not.
• Corpus snapshots byte-identical.
• npm run verify green.

Parent: #653. Roadmap item 5(c) of #646.