feat: add stickiness round — daily Sadaqah tracker + Family Tree social loop

Two features scoped from the stickiness brainstorm, sharing one digest
notification pipeline:

Sadaqah tracker (new tab): a private daily giving journal, not a payment
processor — the app logs, it never moves money. Streak tracking follows
the proven pattern from dedicated apps (Sidq, Daily Sadaqa). Family
visibility is strictly limited to streak counts via a SECURITY DEFINER
RPC (nf_family_sadaqah_streaks) — amounts, causes, and notes never cross
the member boundary, respecting the Islamic preference for giving
privately. Entries can be dedicated 'in memory of' a deceased person from
the Family Tree, with a memorial count (nf_memorial_sadaqah_count, count
only) surfacing on that person's card.

Family Tree social loop: a 'give sadaqah in memory of' link on every
deceased person's card (cross-tab jump via a small requestedTab store in
nav.js), plus completeness hints (missing birth date, missing photo,
no relationships linked) feeding directly into the existing Coverage
Dashboard recommendations engine rather than a new UI surface.

Daily digest Edge Function + pg_cron (07:00 UTC): batches into one email
per family member per day, sent only when there's real content — tree
activity in the last 24h, a birthday/death-anniversary today, or a
weekly sadaqah recap on Sundays. An empty day sends nothing, deliberately
avoiding the notification-spam failure mode the research flagged.
Protected by a shared secret header since it's cron-invoked, not
user-triggered. Verified with a live manual invocation before relying on
the schedule.

Found and fixed two real bugs in nf_family_sadaqah_streaks during E2E
testing: an ambiguous unqualified 'member_id' column reference colliding
with the function's OUT parameter (42702), and a bigint/int type mismatch
from count(*) (42804) — both would have 400'd on every call in production.

Covered by e2e-sadaqah-tree.cjs (12/12). Full regression: 280/280 across
all suites.

src/lib/db.js

@@ -382,6 +382,41 @@ export async function removeRelationship(id) {
   if (error) throw error;
 }
 
+// ── Sadaqah — private daily journal. Family visibility is limited to
+// streak counts via nf_family_sadaqah_streaks (never amounts/causes/notes).
+export async function listSadaqahLog(familyId, memberId) {
+  const { data, error } = await supabase.from('nf_sadaqah_log').select('*').eq('family_id', familyId).eq('member_id', memberId).order('log_date', { ascending: false });
+  if (error) throw error;
+  return (data || []).map(s => ({
+    id: s.id, logDate: s.log_date, cause: s.cause, amount: s.amount,
+    inMemoryOfPersonId: s.in_memory_of_person_id, notes: s.notes
+  }));
+}
+export async function addSadaqahEntry(familyId, memberId, fields) {
+  const { error } = await supabase.from('nf_sadaqah_log').insert({
+    family_id: familyId, member_id: memberId, log_date: fields.logDate || new Date().toISOString().slice(0, 10),
+    cause: fields.cause || null, amount: fields.amount ? Number(fields.amount) : null,
+    in_memory_of_person_id: fields.inMemoryOfPersonId || null, notes: fields.notes || null
+  });
+  if (error) throw error;
+}
+export async function removeSadaqahEntry(id) {
+  const { error } = await supabase.from('nf_sadaqah_log').delete().eq('id', id);
+  if (error) throw error;
+}
+/** Family-visible streak counts only — no amounts, causes, or notes. */
+export async function getFamilySadaqahStreaks(familyId) {
+  const { data, error } = await supabase.rpc('nf_family_sadaqah_streaks', { p_family_id: familyId });
+  if (error) throw error;
+  return (data || []).map(r => ({ memberId: r.member_id, currentStreak: r.current_streak, gaveToday: r.gave_today }));
+}
+/** Count of sadaqah given in memory of a person — count only, shown on their Tree card. */
+export async function getMemorialSadaqahCount(personId) {
+  const { data, error } = await supabase.rpc('nf_memorial_sadaqah_count', { p_person_id: personId });
+  if (error) throw error;
+  return data || 0;
+}
+
 // ── Insurance / Takaful — per-member: each family member logs their own
 // policies, but any family member (and the mutawalli dashboard) can read them. ──
 export async function listInsurancePolicies(familyId, memberId) {