refactor: restructure navigation into 5 grouped hubs, off the 22-item flat strip

Implements the researched IA fix: mobile nav UX consensus caps primary
destinations at 4-5 (uxpin.com, fintech/banking 2026 UX research), and
this app had grown to 22 tabs in one horizontally-scrolling row —
exactly the anti-pattern that research flags for choice paralysis and
slower task completion.

New structure — 5 bottom-nav hubs, grouped by what the user is actually
trying to do, not build order:
- Home: Coverage (unchanged, still the landing screen)
- Estate: Assets, Faraid, Insurance, Wassiyah, Hibah, Family Waqf,
  Nominate, Claims (H2)
- Giving: Zakat, Sadaqah, Khairat
- Family: Tree, Trigger, Mutawalli, Manage (was 'Family', renamed to
  avoid colliding with the hub's own label), Neighbourhood
- Daily: Prayer Times, Qibla, Quran, Locate

Each hub reveals its own sub-nav one tap in, instead of every tab
competing for space in a single row. Settings moved out of the tab
strip entirely into a header gear icon, matching the banking-app pattern
of keeping settings out of primary thumb-reach real estate. The bottom
nav is now fixed (thumb-zone), sub-nav keeps the old sticky-top position.

Cross-component navigation (nav.js requestedTab, used by the Family
Tree's 'give sadaqah in memory' link) now resolves a tab label to its
owning (hub, sub-tab) pair instead of a flat index — verified live.

This touches every E2E suite: a single click on a tab's old selector no
longer reaches it (hub, then sub-tab). Added a shared gotoTab(page, label)
helper to e2e-auth-helper.cjs encapsulating the two-step navigation, and
migrated all ~22 affected test files off direct nav-button selectors —
mechanical substitution followed by manual fixes for local clickTab
wrappers, template-literal selectors, and active-state assertions that
needed to target the new .hub-tab/.subnav structure specifically.

Full regression after migration: every suite passes (one isolated
Family Tree flake confirmed clean on rerun, unrelated to navigation).

e2e-auth-helper.cjs

@@ -22,4 +22,37 @@ async function signInFreshFamily(page, BASE, familyLabel) {
   return familyName;
 }
 
-module.exports = { signInFreshFamily, OWNER_EMAIL, OWNER_PASSWORD };
+// Hub map mirroring App.svelte's HUBS config — the nav went from a single
+// flat 22-item strip to 5 bottom-nav hubs, each revealing its own sub-nav.
+// Reaching any given tab is now a two-step click (hub, then sub-tab)
+// instead of one, so every test goes through this helper rather than
+// hardcoding the old single-click selector.
+const HUB_OF_TAB = {
+  'Coverage': 'Home',
+  'Assets': 'Estate', 'Faraid': 'Estate', 'Insurance': 'Estate', 'Wassiyah': 'Estate',
+  'Hibah': 'Estate', 'Family Waqf': 'Estate', 'Nominate': 'Estate', 'Claims (H2)': 'Estate',
+  'Zakat': 'Giving', 'Sadaqah': 'Giving', 'Khairat': 'Giving',
+  'Tree': 'Family', 'Trigger': 'Family', 'Mutawalli': 'Family', 'Manage': 'Family', 'Neighbourhood': 'Family',
+  'Prayer Times': 'Daily', 'Qibla': 'Daily', 'Quran': 'Daily', 'Locate': 'Daily'
+};
+
+/** Navigates to a tab by its old flat label — clicks the owning hub first (if not already active), then the sub-tab. 'Settings' is a special case (a header icon, not a hub). */
+async function gotoTab(page, label) {
+  if (label === 'Settings') {
+    await page.locator('button[aria-label="Settings"]').click();
+    return;
+  }
+  const hub = HUB_OF_TAB[label];
+  if (!hub) throw new Error(`gotoTab: unknown tab label "${label}"`);
+  const hubBtn = page.locator(`.hub-tab[aria-label="${hub}"]`);
+  const alreadyActive = await hubBtn.evaluate(el => el.classList.contains('active')).catch(() => false);
+  if (!alreadyActive) {
+    await hubBtn.click();
+    await page.waitForTimeout(200);
+  }
+  if (hub !== 'Home') {
+    await page.locator(`.subnav .tab[aria-label="${label}"]`).click();
+  }
+}
+
+module.exports = { signInFreshFamily, OWNER_EMAIL, OWNER_PASSWORD, gotoTab };