feat: close final competitive gap — professional review workflow + multi-country (MY/SG/UK)

Closes the 4th and final gap from the competitive benchmark: the
human-in-the-loop professional tier every commercial competitor pairs
with their software. Deliberately NOT a marketplace or payment
integration — a structured review-request status on each member's
Wassiyah (not_requested -> requested -> reviewed, with reviewer name
recorded), surfaced on the Mutawalli dashboard so nothing quietly ships
as final without the legally-required review being flagged.

Paired with a new whole-app jurisdiction setting since 'necessary in
certain countries' only makes sense per-jurisdiction:

- nf_families.jurisdiction (MY/SG/UK), owner-only to change — first
  UPDATE policy ever added to nf_families, which previously had none.
- New Settings-tab jurisdiction selector (JurisdictionSetting.svelte).
- Wassiyah tab and the draft will document now carry jurisdiction-
  specific legal notes: Wills Act 1959 + state Syariah (Malaysia),
  Wills Act 1838 + AMLA (Singapore), Wills Act 1837 (UK). Singapore
  added as a full third jurisdiction option, not just a stub.
- Zakat calculator's currency label and Nisab default now follow the
  family's jurisdiction (RM/SGD/GBP) instead of a hardcoded RM guess.

Covered by e2e-jurisdiction-review.cjs (13/13). Full regression:
253/253 across all suites (2 reruns confirmed as pre-existing
parallel-load flakes, not regressions).

src/lib/family.js

@@ -104,6 +104,18 @@ export async function removeMember(membershipId) {
   if (error) throw error;
 }
 
+/** Whole-app jurisdiction (MY/SG/UK) — drives Wassiyah legal notes, will
+ * document format, and Zakat currency defaults. Owner-only to change. */
+export async function getFamilyJurisdiction(familyId) {
+  const { data, error } = await supabase.from('nf_families').select('jurisdiction').eq('id', familyId).maybeSingle();
+  if (error) throw error;
+  return data?.jurisdiction || 'MY';
+}
+export async function setFamilyJurisdiction(familyId, jurisdiction) {
+  const { error } = await supabase.from('nf_families').update({ jurisdiction }).eq('id', familyId);
+  if (error) throw error;
+}
+
 export function getActiveFamilyId() {
   let id;
   activeFamilyId.subscribe(v => id = v)();