fix: hand-corrected CQ/ITU zones came back wrong at every restart

The profile's MY_* metadata is derived from the callsign through cty.dat, and the
effect that derives it ran on every load — so opening the settings counted as
"the source changed" and overwrote whatever the operator had typed. Reported by
an operator in CQ 4 / ITU 4 handed 5 and 9: he corrected them, and each restart
put 5 and 9 back.

cty.dat gives the zones of the ENTITY, and a large country spans several, so the
automatic value cannot be treated as authoritative — it is a starting point. A
load now fills only fields that are EMPTY; a recompute that overwrites happens
only when the callsign or grid itself changes, which is the case the derivation
exists for.

The load-vs-edit distinction is a ref holding the profile id the values were last
derived from — first sight of a profile is a load.

changelog.json

@@ -1,4 +1,14 @@
 [
+  {
+    "version": "0.21.9",
+    "date": "2026-07-28",
+    "en": [
+      "CQ and ITU zones you correct by hand in your profile stay corrected. They are derived from cty.dat, which gives the zones of the whole entity — in a country spanning several, the automatic value is wrong and it came back at every restart. They now only fill in when empty, and recompute when the callsign or grid changes."
+    ],
+    "fr": [
+      "Les zones CQ et ITU corrigées à la main dans votre profil restent corrigées. Elles proviennent de cty.dat, qui donne les zones de l'entité entière — dans un pays qui en couvre plusieurs, la valeur automatique est fausse et revenait à chaque redémarrage. Elles ne se remplissent désormais que si le champ est vide, et se recalculent quand l'indicatif ou le locator change."
+    ]
+  },
   {
     "version": "0.21.8",
     "date": "2026-07-28",

frontend/src/components/SettingsModal.tsx

@@ -1483,27 +1483,49 @@ export function SettingsModal({ onClose, onSaved, initialSection, onMainPaneChan
     return () => { off(); };
   }, []);
 
+  // Which (profile, callsign, grid) the auto-fill below last derived from.
+  // Without it, simply OPENING the settings counted as "the source changed" and
+  // overwrote the operator's own values.
+  const derivedFrom = useRef<string>('');
+
   // Auto-fill the active profile's MY_* DXCC metadata from the station
-  // callsign (country, DXCC#, CQ/ITU zones) and the grid (lat/lon). These
-  // are derived values, so they always recompute when the callsign or grid
-  // changes — the user can still edit a field, it just re-populates when the
-  // source changes. Debounced so we don't hammer cty.dat while typing.
+  // callsign (country, DXCC#, CQ/ITU zones) and the grid (lat/lon).
+  //
+  // These are derived values, so they recompute when the callsign or grid
+  // changes. What they must NOT do is recompute on a plain load: cty.dat gives
+  // the zones of the ENTITY, and a large country spans several — an operator in
+  // CQ 14 / ITU 27 was handed 15 and 28 and corrected them by hand, and every
+  // restart put the wrong pair back. cty.dat is a starting point, not an
+  // authority, so on a load we only fill fields that are EMPTY; a value the
+  // operator typed stays until the callsign or grid itself changes.
+  // Debounced so we don't hammer cty.dat while typing.
   useEffect(() => {
     const call = (activeProfile?.callsign ?? '').trim();
     if (!call) return;
     const grid = (activeProfile?.my_grid ?? '').trim();
+    const source = `${activeProfile?.id ?? 0}|${call.toUpperCase()}|${grid.toUpperCase()}`;
+    // First sight of this profile — a load, not an edit.
+    const isLoad = derivedFrom.current === '' || derivedFrom.current.split('|')[0] !== String(activeProfile?.id ?? 0);
     const t = window.setTimeout(async () => {
       try {
         const i: any = await ComputeStationInfo(call, grid);
+        derivedFrom.current = source;
         setActiveProfile((p) => {
           if (!p) return p;
           const patch: any = {};
-          if (i.country) patch.my_country = i.country;
-          if (i.dxcc) patch.my_dxcc = i.dxcc;
-          if (i.cqz) patch.my_cqz = i.cqz;
-          if (i.ituz) patch.my_ituz = i.ituz;
-          if (i.lat) patch.my_lat = i.lat;
-          if (i.lon) patch.my_lon = i.lon;
+          // On a load, keep in patch only what the profile does not already have.
+          const put = (k: string, v: any) => {
+            if (!v) return;
+            const cur = (p as any)[k];
+            if (isLoad && cur !== undefined && cur !== null && cur !== '' && cur !== 0) return;
+            patch[k] = v;
+          };
+          put('my_country', i.country);
+          put('my_dxcc', i.dxcc);
+          put('my_cqz', i.cqz);
+          put('my_ituz', i.ituz);
+          put('my_lat', i.lat);
+          put('my_lon', i.lon);
           // Only re-render when a value actually changed (prevents loops).
           const changed = Object.keys(patch).some((k) => (p as any)[k] !== patch[k]);
           return changed ? { ...p, ...patch } : p;