feat: add Russian-language support to the corrections signal (#6)

[HumanBean17]

Closes #6.

Why

The corrections signal's keyword catalog (src/adapter/correction.ts) was English-only, so Russian course-corrections (нет, не туда, стоп, отмена, …) went undetected — they never set the correction flag, under-counting friction on any EN/RU bilingual session. DESIGN.md §4.2 already listed «не туда» as a correction example.

What changed

• Additive per-language catalog. Replaced the hardcoded English token arrays with LANG_CATALOGS: { en, ru }, mapped to the same four shape values. Per-shape token lists are merged + normalized + deduped once at module load; the matching loop is language-agnostic. Adding a language is now a catalog-only change — no matching-logic edits. Latin/Cyrillic are disjoint scripts, so the merge cannot introduce cross-language bleed.
• Cyrillic normalization at the input boundary, applied symmetrically to both input text and tokens: lowercase, ё→е, curly/smart quotes → straight apostrophe, every other non-letter/digit/apostrophe → space, whitespace collapse. So «нет,» ≡ нет, ещё ≡ еще, and hyphenated по-другому unifies with its two-word form.
• Unicode word boundary. startsWithToken now uses \p{L} for continuation, so нет no longer matches нетворк / неточный — and the prior English semantics (apostrophe + digit = boundary) are preserved exactly.
• Privacy contract intact. Still emits only {matched, shape}; raw text is consumed and discarded.

Tests

• test/correction.test.ts: RU coverage across all four shapes; affirmations (да/отлично/точно) do not match; normalization («нет,», стоп!, ё→е cross-form); word-boundary anti-false-positives (нетворк/неточный); cross-language bleed; shape-precedence lock (по-другому → redirect).
• test/privacy.test.ts §(f): pipeline-level Russian prose-leak assertion across human/json/calibrate + warnings, with a load-bearing corrections >= 1 check proving the text was actually ingested/detected (so non-leak isn't vacuously true).
• No English regression — all 11 prior correction.test.ts cases stay green.

Docs

EN+RU note added to CONSUMER_GUIDE.md (FAQ), DESIGN.md §4.2, and the ARCHITECTURE.md module-table row.

Verification

npm run build ✓ · tsc --noEmit ✓ · 423 tests pass.

Review

Reviewed via requesting-code-review (3 parallel reviewers: detector core / tests+privacy / docs). No Critical. Applied: неверно one-word synonym gap, vacuous ё→е test fix, privacy §(f) load-bearing assertion, misleading да test rationale, dead по-другому duplicate removal, precedence-comment correction, positive-precedence + cross-bleed test strengthening, "stripped"→"ignored" wording. Accepted as-is: bare no, length-floor edge, short-token substring FP risk (consistent with pre-existing English), micro-allocation.

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