health_persistence: stop leaking obs counts across NVMe device renames

`get_disks_observation_counts` maps each serial's count to that
serial's "most recent" device_name (so renames like ata8 -> sdh keep
the badge attached). When several physical disks have passed through
the same kernel name across reboots — common with NVMe, the kernel
probes in a different order depending on which slots are populated —
disk_registry keeps a row per (device_name, serial) seen and the
"most recent" device_name for a serial can now be in use by an
entirely different disk.

Concrete case from the wild: serial 211716800490 was nvme0n1 during
the previous boot and earned a real I/O observation. After removing
four of five NVMes, the surviving disk (serial 243332800236) booted
into nvme0n1. The badge layer mirrored 211716800490's count onto
nvme0n1 — which is now a different physical disk — and showed
"1 obs." on the wrong drive, while the modal (which scopes by the
current (device_name, serial) registry row) found nothing and
rendered an empty history.

Only mirror a serial's count onto its device_name when that
device_name is currently owned by the same serial, determined from
the freshest disk_registry row. The serial-keyed entry stays
unconditional so observations remain reachable when the disk is
re-plugged under another device name.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

AppImage/scripts/health_persistence.py

@@ -2592,12 +2592,34 @@ class HealthPersistence:
                 if serial not in serial_to_device:
                     serial_to_device[serial] = device_name
             
+            # Resolve which serial currently OWNS each device_name. The
+            # kernel reuses NVMe / SD device names across reboots
+            # (e.g. the disk that was nvme4n1 with 5 NVMes plugged in
+            # comes back as nvme0n1 once 4 are removed), and
+            # disk_registry keeps a row for every (device_name, serial)
+            # combination it has ever seen. Without this check we would
+            # mirror an observation's count onto its serial's
+            # "most-recent" device_name even when that name is now in
+            # use by a DIFFERENT serial — surfacing a "1 obs." badge on
+            # a disk that has no observations of its own and a clean
+            # modal, since the modal correctly scopes by current
+            # (device_name, serial) pair.
+            cursor.execute('''
+                SELECT device_name, serial FROM disk_registry
+                WHERE device_name IS NOT NULL AND device_name != ''
+                ORDER BY last_seen DESC
+            ''')
+            current_owner = {}
+            for device_name, dev_serial in cursor.fetchall():
+                if device_name not in current_owner:
+                    current_owner[device_name] = dev_serial
+
             # Build result
             result = {}
             for serial, cnt in serial_counts.items():
                 result[f'serial:{serial}'] = cnt
                 device_name = serial_to_device.get(serial)
-                if device_name:
+                if device_name and current_owner.get(device_name) == serial:
                     result[device_name] = max(result.get(device_name, 0), cnt)
             
             # For disks WITHOUT serial: group by device_name