i18n: 'dv' (Divehi) locale missing CLDR 'many' plural category on 3 keys #197

`dv.ts` (Divehi) only has `.one`/`.other` for these 3 keys, missing the `.many` category that Divehi's CLDR plural rules require:

• `session.question.pending.many`
• `session.followupDock.summary.many`
• `session.revertDock.summary.many`

Confirmed pre-existing on `dev` HEAD — identical in that branch, unrelated to any currently open PR. It was masked in `src/i18n/parity.test.ts` until now because the test loop bails at the first failing locale in `appLocales` order, and `ar` (which comes before `dv`) had its own missing-keys failure (fixed directly in PR #161) that was masking this one.

Needs an actual Divehi translation for the "many" plural form on these 3 strings — not a mechanical fix, left for someone who can translate. `src/i18n/parity.test.ts`'s second and third test cases (placeholder parity, plural parity) also fail as a side effect of this gap (a TypeError on undefined the plural test doesn't guard against, plus the same missing-key mismatch).