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-zakat.cjs

@@ -2,7 +2,7 @@
 // correct 2.5% due once above Nisab, values autosave and persist across a
 // remount, and a fresh family (same account) doesn't see this member's figures.
 const { chromium } = require('playwright');
-const { signInFreshFamily } = require('./e2e-auth-helper.cjs');
+const { signInFreshFamily, gotoTab } = require('./e2e-auth-helper.cjs');
 const BASE = 'https://moslem04.falahos.my/';
 const results = [];
 const consoleErrors = [];
@@ -15,7 +15,7 @@ async function main() {
   page.on('pageerror', e => consoleErrors.push(e.message));
 
   await signInFreshFamily(page, BASE, 'e2e-zakat');
-  await page.locator('nav button[aria-label="Zakat"]').click();
+  await gotoTab(page, 'Zakat');
   await page.waitForTimeout(600);
 
   // Below nisab: default nisab is 24000, wealth 10000 -> no zakat due
@@ -41,9 +41,9 @@ async function main() {
   record('Zakat: deductible liabilities reduce zakatable wealth', wealthAfterDebt.trim() === '35,000', wealthAfterDebt);
 
   // Persistence: reload the tab (remount) and confirm autosave held
-  await page.locator('nav button[aria-label="Coverage"]').click();
+  await gotoTab(page, 'Coverage');
   await page.waitForTimeout(400);
-  await page.locator('nav button[aria-label="Zakat"]').click();
+  await gotoTab(page, 'Zakat');
   await page.waitForTimeout(800);
   const cashPersisted = await page.locator('.field:has-text("Cash") input').inputValue();
   record('Zakat: autosaved figures persist across a tab remount', cashPersisted === '30000', cashPersisted);
@@ -51,7 +51,7 @@ async function main() {
   // Isolation: a different family (same account) starts with defaults, not this member's figures
   const isolationPage = await browser.newPage({ viewport: { width: 390, height: 844 } });
   await signInFreshFamily(isolationPage, BASE, 'e2e-zakat-isolation');
-  await isolationPage.locator('nav button[aria-label="Zakat"]').click();
+  await gotoTab(isolationPage, 'Zakat');
   await isolationPage.waitForTimeout(600);
   const isolatedCash = await isolationPage.locator('.field:has-text("Cash") input').inputValue();
   record('Isolation: a different family does not see this member\'s Zakat figures', isolatedCash === '', isolatedCash);