docs(i18n): copy-edit the English to newspaper style

[eaitbrahim]

Closes #37.

Scope note, up front. The English was not in the state the Arabic was in
#34. It is authored, not translated — no broken words, no factual bugs, no
mistranslations. What it had was a copy-editing backlog. So this is a
copy-edit, not a rewrite: the register stays, and no headline or honest-framing
sentence was softened.

Fixed

A number with no noun. features.ts: "the same rules on ONE_HOUR bars fire
49.4". The unit — signals per asset-year — sat in the previous clause and never
came back. It read as a typo.

Six sentences ran 40 to 54 words. The longest, install.ts's code-signing
paragraph, is now four sentences. Nothing over 38 words remains, and what is
left is parallel enumeration where the length is doing work.

Dash density. home.ts's honest-result paragraph carried four em dashes;
compare.ts's footnote carried three. One dash-set aside per sentence now.

Quote marks. about.ts used curly quotes for “open source” and escaped
straight quotes for "keel trading", three answers apart. community.ts was
straight throughout. All curly now.

Brand capitalisation. home.ts's <title> read "Keel: Open-Source Shariah
Compliance Engine for Crypto" — the only English string capitalising the brand.

A CLI literal in two forms. "a GO-LIVE / TRAIN-MORE report", then "tell you
TRAIN MORE", one sentence apart, in features.ts and install.ts.

Unglossed jargon on the pages where a search visitor first meets it:
PBO/CSCV is now expanded as the probability of backtest overfitting computed
by combinatorially symmetric cross-validation; bp is basis points; "per leg"
is "on each side of a trade"; "fails closed" gets a clause on the home page.

SEO. compare.ts's meta description was 177 characters and would have
truncated. Now 132. Everything else sits between 135 and 157.

Constructions: "Apache-2.0 cannot be un-free'd", "the whole gauntlet
exercised in production", "Venue breadth is deliberately not chased", "Said
upfront so step four is not a surprise", "the tried-vs-used ledger", and
"practised" where every other spelling in the repo is US.

Style sheet

CONTRIBUTING.md gains a Prose style section — dash limit, sentence length,
gloss-per-page, figures, brand case, quote marks, CLI literals, spelling, meta
length. The point is that the next page follows the rules rather than
re-deriving them.

Three French strings, despite French being deferred

The home <title> brand capitalisation, the TRAIN-MORE CLI literal, and the
PBO/CSCV expansion. These are cross-cutting consistency rather than a French
style pass, and leaving them inconsistent after fixing English and Arabic would
have been worse. The equivalent Arabic gloss was added as well, so rev and
translatedFromRev move together and no page shows a spurious stale banner.

French prose itself is still untouched and still wants its own pass.

Verification

• npx tsc --noEmit clean
• npm run build green — 41 pages
• Re-ran the measurements from i18n(en): copy-edit every page's English to newspaper style #37: no string over two em dashes, no sentence
  over 38 words, no meta description over 160, no ~ left in English prose

🤖 Generated with Claude Code

https://claude.ai/code/session_01EURzVpngXDN1dk9c5FMFhW

[sonarqubecloud]

Quality Gate failed

Failed conditions
73.6% Duplication on New Code (required ≤ 3%)

See analysis details on SonarQube Cloud