Generalize the shared concept space with an exact-match reuse discipline

[konard]

Context

Issue #47 requires "advanced shared concepts space between languages, which
should be reused when only matched exactly, so it will help to simplify
automated translation between any languages". The 351-concept lexicon
(seed_common_concept_ontology) and reference_for_atom exact-find_term
reuse exist, but concepts are not interned across languages under a stated
exact-match discipline, and concept-mediated translation is demo-grade. See
requirements.md R-6 and
solution-plans.md S-9.

Research (competitors-natural-language.md):
Wikidata's two-layer design (language-bound lexeme ↔ language-free Q-item,
all CC0) is the friction-free model; WordNet CILI institutionalizes exactly
the issue's rule - reuse an interlingual id only on exact match, otherwise
mint a new one. BabelNet is rejected (non-commercial license, API-gated).

Scope

• Two-layer concept links: language-bound expression links connected to
  language-free concept links; reuse a concept only on exact-id match,
  otherwise mint a new concept link.
• Alias links on concepts for external ids (WordNet CILI ILI ids, Wikidata
  Q-ids) so external vocabularies can be attached without becoming load-bearing.
• Generalize seed_common_concept_ontology into an import surface that loads
  concept sets from LiNo files, keeping the 351-concept seed as the default.
• Tests proving the exact-match rule: same id → same link reused; near-miss
  (case, diacritics, sense) → new concept minted.

Acceptance criteria

• Concept interning API with the exact-match rule, gated by tests
  including near-miss cases.
• External-id alias links queryable via LinkQuery.
• Concept import from LiNo round-trips through the ontology.
• Changelog fragment added (bump: minor).

References

• Requirement: requirements.md R-6
• Solution: solution-plans.md S-9
• Part of We need to carefully compare all competitors in all scopes with out project, and make sure we have the richest features set #47; work lands on branch issue-47-76af108c0f24 (PR Finish issue #47 parity feature set #48).

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Filed from docs/case-studies/issue-47/proposed-issues/09-shared-concept-space-exact-match.md. Part of the implementation plan for #47.