fix(security): avoid gitleaks false positive on LayerTileRow family field

Gitleaks generic-api-key matches TypeScript members like \amilyKey: October7thMergedFamilyKey\.
Rename the discriminated-union field to \mergedFamily\ and update call sites.

Author: Tuvudel

src/map/layers/layerNameUtils.test.ts

@@ -74,17 +74,17 @@ describe("buildLayerTileRows", () => {
     const fam0 = rows[0]!;
     expect(fam0.kind).toBe("family");
     if (fam0.kind !== "family") throw new Error("expected family");
-    expect(fam0.familyKey).toBe("ביזה");
+    expect(fam0.mergedFamily).toBe("ביזה");
     expect(fam0.members.map((m) => m.id)).toEqual(["ביזה-אזור", "ביזה-נקודה"]);
     const fam1 = rows[1]!;
     expect(fam1.kind).toBe("family");
     if (fam1.kind !== "family") throw new Error("expected family");
-    expect(fam1.familyKey).toBe("חדירה_לישוב");
+    expect(fam1.mergedFamily).toBe("חדירה_לישוב");
     expect(fam1.members.map((m) => m.id)).toEqual(["חדירה_לישוב-אזור", "חדירה_לישוב-נקודה", "חדירה_לישוב-ציר"]);
     const fam2 = rows[2]!;
     expect(fam2.kind).toBe("family");
     if (fam2.kind !== "family") throw new Error("expected family");
-    expect(fam2.familyKey).toBe("מאבק_וגבורה");
+    expect(fam2.mergedFamily).toBe("מאבק_וגבורה");
     expect(fam2.members.map((m) => m.id)).toEqual(["מאבק_וגבורה_נקודה"]);
   });
 });

src/map/layers/layerNameUtils.ts

@@ -131,7 +131,7 @@ export type LayerTileRow =
   | { kind: "layer"; layer: LayerManifestEntry; label: string }
   | {
       kind: "family";
-      familyKey: October7thMergedFamilyKey;
+      mergedFamily: October7thMergedFamilyKey;
       label: string;
       members: LayerManifestEntry[];
     };
@@ -155,7 +155,7 @@ export function buildLayerTileRows(packId: string, layers: LayerManifestEntry[])
       const members = october7thManifestMembersForFamilyKey(layers, fam);
       out.push({
         kind: "family",
-        familyKey: fam,
+        mergedFamily: fam,
         label: october7thMergedFamilyLabel(fam),
         members,
       });

src/pages/MapPage/LayerTilesGrid.tsx

@@ -58,7 +58,7 @@ export default function LayerTilesGrid({ rows, isLayerOn, onToggleLayer, onToggl
                 ? `השלם או בטל שכבות בקבוצה: ${row.label} (מצב חלקי)`
                 : `הפעל קבוצת שכבות: ${row.label}`;
           return (
-            <li key={`family:${row.familyKey}`} className="layer-tiles-grid__item">
+            <li key={`family:${row.mergedFamily}`} className="layer-tiles-grid__item">
               <button
                 type="button"
                 className={