Add NFC chore submission feature and enhance family settings

- Introduced NFC support for chore submissions, allowing specific person credit after Head of Household approval.
- Updated family settings to include NFC base URL, scan cooldown, and confirmation page options.
- Enhanced chore management with options for anyone to complete chores and NFC link generation.
- Improved API endpoints for handling NFC tokens and chore submissions.
- Updated readme to reflect new NFC features and settings.

includes/family_settings.php

@@ -34,6 +34,9 @@ function familySettingsDefaultsRaw(): array {
         'week_starts_on' => 0,
         'calendar_two_way_google' => false,
         'calendar_bill_days' => [],
+        'nfc_base_url' => '',
+        'nfc_show_confirmation' => true,
+        'nfc_scan_cooldown_seconds' => 0,
     ];
 }
 
@@ -80,6 +83,11 @@ function normalizeLoadedFamilySettings(array $s): array {
     $v = $s['calendar_two_way_google'] ?? false;
     $s['calendar_two_way_google'] = $v === true || $v === 1 || $v === '1' || $v === 'true';
     $s['calendar_bill_days'] = normalizeCalendarBillDaysRaw($s['calendar_bill_days'] ?? []);
+    $s['nfc_base_url'] = trim((string) ($s['nfc_base_url'] ?? ''));
+    $showConfirmation = $s['nfc_show_confirmation'] ?? true;
+    $s['nfc_show_confirmation'] = $showConfirmation === true || $showConfirmation === 1 || $showConfirmation === '1' || $showConfirmation === 'true';
+    $cooldown = (int) ($s['nfc_scan_cooldown_seconds'] ?? 0);
+    $s['nfc_scan_cooldown_seconds'] = max(0, min(600, $cooldown));
     return $s;
 }
 
@@ -96,6 +104,28 @@ function loadFamilySettings(): array {
     return normalizeLoadedFamilySettings($merged);
 }
 
+/**
+ * Base app URL (without trailing slash) used for externally shared links.
+ */
+function familyHubAppUrl(array $familySettings): string {
+    $base = trim((string) ($familySettings['nfc_base_url'] ?? ''));
+    if ($base !== '') {
+        return rtrim($base, '/');
+    }
+    $https = !empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off';
+    $scheme = $https ? 'https' : 'http';
+    $host = trim((string) ($_SERVER['HTTP_HOST'] ?? 'localhost'));
+    $script = trim((string) ($_SERVER['SCRIPT_NAME'] ?? '/index.php'));
+    $dir = rtrim(str_replace('\\', '/', dirname($script)), '/');
+    if ($dir === '' || $dir === '.') {
+        $dir = '';
+    }
+    if (substr($dir, -4) === '/api') {
+        $dir = substr($dir, 0, -4);
+    }
+    return $scheme . '://' . $host . $dir;
+}
+
 /**
  * Tab label: symbol + name (e.g. "★ Stars").
  */