fix(events): avoid transient pending files in JSONL tests

src/nativeTest/java/games/dmg/fantasystick/FantasyStickLifecycleNativeTest.java

@@ -701,12 +701,39 @@ class FantasyStickLifecycleNativeTest {
         }
     }
 
+    @Test void nativeJsonlReaderSeesExportedUtcSegmentsButNotTransientPendingArea() throws Exception {
+        var root=data.resolve("events");
+        var first=java.nio.file.Files.createDirectories(root.resolve("2026-09-27"));
+        var second=java.nio.file.Files.createDirectories(root.resolve("2026-09-28"));
+        var pending=java.nio.file.Files.createDirectories(root.resolve("pending"));
+        java.nio.file.Files.writeString(first.resolve("events-first-0.jsonl"),"{\"id\":\"first\"}\n");
+        java.nio.file.Files.writeString(second.resolve("events-second-0.jsonl"),"{\"id\":\"second\"}\n");
+        // This is never an exported segment, even if a transient file resembles one.
+        java.nio.file.Files.writeString(pending.resolve("decoy.jsonl"),"{\"id\":\"pending\"}\n");
+        java.nio.file.Files.writeString(pending.resolve("in-flight.pending"),"uncommitted");
+        assertEquals(List.of("first","second"),localRecords(data).stream()
+            .map(record->record.get("id").getAsString()).sorted().toList());
+        java.nio.file.Files.writeString(second.resolve("events-second-0.jsonl"),"{\"broken\":\n");
+        assertThrows(com.google.gson.JsonParseException.class,()->localRecords(data),
+            "a malformed exported record must not be hidden by excluding pending files");
+    }
+
     private static java.util.List<com.google.gson.JsonObject> localRecords(Path directory) throws IOException {
         var events = new java.util.ArrayList<com.google.gson.JsonObject>();
-        try (var files = java.nio.file.Files.walk(directory.resolve("events"))) {
-            for (var path : files.filter(p -> p.getFileName().toString().endsWith(".jsonl")).toList())
-                for (var line : java.nio.file.Files.readAllLines(path))
-                    if (!line.isBlank()) events.add(com.google.gson.JsonParser.parseString(line).getAsJsonObject());
+        // Exported segments live directly under UTC-date directories. Never traverse
+        // pending/: its files can disappear while the asynchronous writer exports them.
+        try (var dates = java.nio.file.Files.list(directory.resolve("events"))) {
+            for (var date : dates.filter(java.nio.file.Files::isDirectory)
+                    .filter(p -> p.getFileName().toString().matches("\\d{4}-\\d{2}-\\d{2}"))
+                    .toList()) {
+                try (var segments = java.nio.file.Files.list(date)) {
+                    for (var path : segments.filter(java.nio.file.Files::isRegularFile)
+                            .filter(p -> p.getFileName().toString().startsWith("events-")
+                                && p.getFileName().toString().endsWith(".jsonl")).toList())
+                        for (var line : java.nio.file.Files.readAllLines(path))
+                            if (!line.isBlank()) events.add(com.google.gson.JsonParser.parseString(line).getAsJsonObject());
+                }
+            }
         }
         return events;
     }