fix: health monitor stabilization pass for all pineapd crash sources

Field-verified crash stack on this firmware: SSID-pool broadcast (segfault),
wlan2mon hopping a nonexistent 6GHz iface (segfault), wlan1mon fast-hopping
6GHz channels (ASIO thread exit), and a large refilled pool. The fix path
now enforces: pool broadcast off, pool list cleared, wlan2mon off, wlan1mon
5GHz-only, wlan0mon 2.4GHz-only — idempotent, so collect refills self-heal.
8-minute continuous-PONG stability verified on-device.

tests/test_health.py

@@ -66,16 +66,28 @@ class HealthCheckTest(unittest.TestCase):
         self.ping_ok = False
         self.uci_state['pineapd.@ssidpool[0].disable'] = '1'
         self.uci_state['pineapd.wlan2mon.disable'] = '1'
+        self.uci_state['pineapd.wlan2mon.hop'] = '0'
+        self.uci_state['pineapd.wlan1mon.bands'] = '5'
+        self.uci_state['pineapd.wlan0mon.bands'] = '2'
         result = server.health_check()
         self.assertEqual(result['last_action'], 'pineapd restart')
         self.assertIn(['/etc/init.d/pineapd', 'restart'], [r[0] for r in self.runs])
 
-    def test_down_disables_wlan2mon_crash_source(self):
+    def test_down_stabilizes_known_crash_sources(self):
         self.ping_ok = False
         self.uci_state['pineapd.@ssidpool[0].disable'] = '1'
         result = server.health_check()
-        self.assertEqual(result['last_action'], 'wlan2mon disabled (missing 6GHz iface crash source)')
         self.assertEqual(self.uci_state['pineapd.wlan2mon.disable'], '1')
+        self.assertEqual(self.uci_state['pineapd.wlan1mon.bands'], '5')
+        self.assertIn('stabilized', result['last_action'])
+
+    def test_down_clears_refilled_pool_list(self):
+        self.ping_ok = False
+        self.uci_state['pineapd.@ssidpool[0].disable'] = '1'
+        self.uci_state['pineapd.@ssidpool[0].ssid'] = 'QmVlcg=='
+        result = server.health_check()
+        self.assertNotIn('pineapd.@ssidpool[0].ssid', self.uci_state)
+        self.assertIn('pool-list cleared', result['last_action'])
 
     def test_down_without_crash_brings_monitors_up(self):
         self.ping_ok = False