v4.23.0 — Chinese documents no longer carry English sentence spacing

Fixed — Chinese documents no longer carry English sentence spacing

Running the Chinese half of the guidance loop (the beam lab report
rewritten to the reader rubric and the structure discipline) exposed a
typography defect that only becomes visible once paragraphs hold several
sentences: Chinese sentences were separated by a space.

Each authored sentence is its own markdown line, and pandoc turns an
intra-paragraph newline into a space — correct for English, wrong for
Chinese, which takes no inter-sentence spacing. Stripped internal-source
markers left the same gap mid-line ("轉動。 千分錶"), as did authored
citation markers ("4.8%。 [1]"). Chinese documents now get a typography
normalization pass before rendering: CJK-to-CJK gaps close, spacing
between Chinese and Latin ("撓度 1.52 mm") is left alone, and tables,
headings, lists, and code fences are untouched. English documents skip
the pass entirely and render byte-identically.

Also verified in this pass: Chinese derived statistics (4.21.0) reach a
rendered document for the first time — the discussion cites the
least-squares slope, R², and mean error in Chinese — and the 4.22.1
duplicate-citation fix holds on the Chinese path.

463 tests, both benchmark --checks, and native end-to-end reruns of both
the Chinese and English lab reports pass.