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/App.svelte

@@ -13,6 +13,7 @@
   import InfoPanel from './lib/InfoPanel.svelte';
   import { session, authLoading, signOut } from './lib/auth.js';
   import { activeFamilyId, listMyFamilies } from './lib/family.js';
+  import { requestedTab } from './lib/nav.js';
   import AuthScreen from './lib/AuthScreen.svelte';
   import FamilySwitcher from './lib/FamilySwitcher.svelte';
   import FamilyManagement from './lib/FamilyManagement.svelte';
@@ -21,6 +22,7 @@
   import InsurancePolicies from './lib/InsurancePolicies.svelte';
   import ZakatCalculator from './lib/ZakatCalculator.svelte';
   import JurisdictionSetting from './lib/JurisdictionSetting.svelte';
+  import SadaqahTracker from './lib/SadaqahTracker.svelte';
 
   let currentLang = $state('en');
   lang.subscribe(v => currentLang = v);
@@ -44,9 +46,15 @@
     }
   });
 
-  const tabs = ['Coverage', 'Faraid', 'Assets', 'Insurance', 'Zakat', 'Wassiyah', 'Hibah', 'Family Waqf', 'Nominate', 'Trigger', 'Mutawalli', 'Tree', 'Claims (H2)', 'Family', 'Settings'];
-  const icons = ['🎯', '📊', '📁', '🛡️', '🌙', '📜', '🎁', '⛲', '📇', '⚡', '🕋', '🌳', '🔗', '👥', '⚙️'];
+  const tabs = ['Coverage', 'Faraid', 'Assets', 'Insurance', 'Zakat', 'Sadaqah', 'Wassiyah', 'Hibah', 'Family Waqf', 'Nominate', 'Trigger', 'Mutawalli', 'Tree', 'Claims (H2)', 'Family', 'Settings'];
+  const icons = ['🎯', '📊', '📁', '🛡️', '🌙', '🤲', '📜', '🎁', '⛲', '📇', '⚡', '🕋', '🌳', '🔗', '👥', '⚙️'];
   let activeTab = $state(0);
+  requestedTab.subscribe(name => {
+    if (!name) return;
+    const idx = tabs.indexOf(name);
+    if (idx >= 0) activeTab = idx;
+    requestedTab.set(null);
+  });
 
   function handleKeydown(e) {
     if (e.key === 'ArrowRight') activeTab = (activeTab + 1) % tabs.length;
@@ -104,16 +112,17 @@
     {:else if activeTab === 2}<AssetRegistry />
     {:else if activeTab === 3}<InsurancePolicies />
     {:else if activeTab === 4}<ZakatCalculator />
-    {:else if activeTab === 5}<WassiyahGenerator />
-    {:else if activeTab === 6}<HibahTracker />
-    {:else if activeTab === 7}<FamilyWaqfDesignator />
-    {:else if activeTab === 8}<NominationRegistry />
-    {:else if activeTab === 9}<DeathTrigger />
-    {:else if activeTab === 10}<MutawalliDashboard />
-    {:else if activeTab === 11}<FamilyTree />
-    {:else if activeTab === 12}<DigitalClaims />
-    {:else if activeTab === 13}<FamilyManagement />
-    {:else if activeTab === 14}
+    {:else if activeTab === 5}<SadaqahTracker />
+    {:else if activeTab === 6}<WassiyahGenerator />
+    {:else if activeTab === 7}<HibahTracker />
+    {:else if activeTab === 8}<FamilyWaqfDesignator />
+    {:else if activeTab === 9}<NominationRegistry />
+    {:else if activeTab === 10}<DeathTrigger />
+    {:else if activeTab === 11}<MutawalliDashboard />
+    {:else if activeTab === 12}<FamilyTree />
+    {:else if activeTab === 13}<DigitalClaims />
+    {:else if activeTab === 14}<FamilyManagement />
+    {:else if activeTab === 15}
       <div class="module">
         <div class="module-header">
           <h2>Settings</h2>