refactor(audience-sdk): name queue file glob and atomic-write tmp suffix

Replaces the hand-rolled "*.json" globs and ".tmp" atomic-write suffixes spread across DiskStore,
ConsentStore, Identity, and the test suite with named constants on AudiencePaths so a rename of
either pattern touches one file and runtime / tests stay in sync.

- AudiencePaths.cs: adds QueueFileExtension (.json), QueueGlob ("*.json"), TempFileSuffix (.tmp).
- DiskStore.cs: queueDir uses AudiencePaths.QueueDir; the "*.json" globs and ".tmp" suffix go
  through the new constants; new file naming uses QueueFileExtension.
- ConsentStore.cs, Identity.cs: atomic-write tmpPath uses AudiencePaths.TempFileSuffix.
- Test suite (DiskStoreTests, SessionTests, ImmutableAudienceTests, ThreadSafetyStressTests):
  Directory.GetFiles globs read from AudiencePaths.QueueGlob.
- SampleAppLiveFireTests.cs: SDK persistence dir comes from AudiencePaths.AudienceDir, so the
  sample-app side no longer needs its own SdkPersistedDirName mirror.

Author: ImmutableJeffrey

examples/audience/Assets/SampleApp/Tests/Runtime/SampleAppLiveFireTests.cs

@@ -36,7 +36,7 @@ public void SetUp()
             // (and identity/queue) to disk under <persistentDataPath>/imtbl_audience.
             // Without wiping it, a SetConsent(None) from a prior test leaks into
             // the next test's Init via ConsentStore.Load.
-            var sdkDir = System.IO.Path.Combine(Application.persistentDataPath, SampleAppUi.SdkPersistedDirName);
+            var sdkDir = AudiencePaths.AudienceDir(Application.persistentDataPath);
             if (System.IO.Directory.Exists(sdkDir))
                 System.IO.Directory.Delete(sdkDir, recursive: true);
 

src/Packages/Audience/Runtime/Core/AudiencePaths.cs

@@ -9,6 +9,13 @@ internal static class AudiencePaths
         private const string ConsentFileName = "consent";
         private const string QueueDirName = "queue";
 
+        // Queue files are named <ticks>_<uuid>.json.
+        internal const string QueueFileExtension = ".json";
+        internal const string QueueGlob = "*" + QueueFileExtension;
+
+        // Files ending in this suffix are mid-write and must not be read.
+        internal const string TempFileSuffix = ".tmp";
+
         internal static string AudienceDir(string persistentDataPath) =>
             Path.Combine(persistentDataPath, RootDirName);
 

src/Packages/Audience/Runtime/Core/ConsentStore.cs

@@ -12,7 +12,7 @@ internal static void Save(string persistentDataPath, ConsentLevel level)
             Directory.CreateDirectory(AudiencePaths.AudienceDir(persistentDataPath));
 
             var filePath = AudiencePaths.ConsentFile(persistentDataPath);
-            var tmpPath = filePath + ".tmp";
+            var tmpPath = filePath + AudiencePaths.TempFileSuffix;
 
             File.WriteAllText(tmpPath, ((int)level).ToString());
 

src/Packages/Audience/Runtime/Core/Identity.cs

@@ -92,7 +92,7 @@ internal static void ClearCache()
                 // New install: generate a UUID and persist it atomically.
                 // Write to a .tmp file first so a crash mid-write leaves no corrupt file.
                 var newId = Guid.NewGuid().ToString();
-                var tmpPath = filePath + ".tmp";
+                var tmpPath = filePath + AudiencePaths.TempFileSuffix;
                 File.WriteAllText(tmpPath, newId);
 
                 try

src/Packages/Audience/Runtime/Transport/DiskStore.cs

@@ -23,17 +23,17 @@ internal sealed class DiskStore
 
         internal DiskStore(string persistentDataPath)
         {
-            _queueDir = Path.Combine(persistentDataPath, "imtbl_audience", "queue");
+            _queueDir = AudiencePaths.QueueDir(persistentDataPath);
             Directory.CreateDirectory(_queueDir);
-            _cachedCount = Directory.GetFiles(_queueDir, "*.json").Length;
+            _cachedCount = Directory.GetFiles(_queueDir, AudiencePaths.QueueGlob).Length;
         }
 
         // Atomically writes json as a new event file.
         internal void Write(string json)
         {
-            var fileName = $"{DateTime.UtcNow.Ticks}_{Guid.NewGuid():N}.json";
+            var fileName = $"{DateTime.UtcNow.Ticks}_{Guid.NewGuid():N}{AudiencePaths.QueueFileExtension}";
             var finalPath = Path.Combine(_queueDir, fileName);
-            var tmpPath = finalPath + ".tmp";
+            var tmpPath = finalPath + AudiencePaths.TempFileSuffix;
 
             File.WriteAllText(tmpPath, json);
 
@@ -66,7 +66,7 @@ internal IReadOnlyList<string> ReadBatch(int maxSize)
             var result = new List<string>();
 
             // Sort by filename (ticks prefix) → oldest first
-            var files = Directory.GetFiles(_queueDir, "*.json")
+            var files = Directory.GetFiles(_queueDir, AudiencePaths.QueueGlob)
                 .OrderBy(f => Path.GetFileName(f), StringComparer.Ordinal);
 
             foreach (var path in files)
@@ -116,7 +116,7 @@ private static bool TryDelete(string path)
         internal void DeleteAll()
         {
             string[] paths;
-            try { paths = Directory.GetFiles(_queueDir, "*.json"); }
+            try { paths = Directory.GetFiles(_queueDir, AudiencePaths.QueueGlob); }
             catch (DirectoryNotFoundException) { return; }
 
             foreach (var path in paths)
@@ -128,7 +128,7 @@ internal void DeleteAll()
         internal void ApplyAnonymousDowngrade()
         {
             string[] paths;
-            try { paths = Directory.GetFiles(_queueDir, "*.json"); }
+            try { paths = Directory.GetFiles(_queueDir, AudiencePaths.QueueGlob); }
             catch (DirectoryNotFoundException) { return; }
 
             foreach (var path in paths)
@@ -179,7 +179,7 @@ private void RewriteTrackWithoutUserId(string path, Dictionary<string, object> m
             try
             {
                 var rewritten = Json.Serialize(msg);
-                var tmp = path + ".tmp";
+                var tmp = path + AudiencePaths.TempFileSuffix;
                 File.WriteAllText(tmp, rewritten);
                 try { File.Move(tmp, path); }
                 catch (IOException)

src/Packages/Audience/Tests/Runtime/Core/SessionTests.cs

@@ -712,7 +712,7 @@ private string[] ReadQueueFiles()
         {
             var queueDir = Path.Combine(_testDir, "imtbl_audience", "queue");
             if (!Directory.Exists(queueDir)) return Array.Empty<string>();
-            return Directory.GetFiles(queueDir, "*.json").Select(File.ReadAllText).ToArray();
+            return Directory.GetFiles(queueDir, AudiencePaths.QueueGlob).Select(File.ReadAllText).ToArray();
         }
 
         [Test]
@@ -811,7 +811,7 @@ public void Reset_StartsNewSession_DoesNotEmitSessionEnd()
             // only see post-Reset events.
             ImmutableAudience.FlushQueueToDiskForTesting();
             var queueDir = Path.Combine(_testDir, "imtbl_audience", "queue");
-            foreach (var f in Directory.GetFiles(queueDir, "*.json")) File.Delete(f);
+            foreach (var f in Directory.GetFiles(queueDir, AudiencePaths.QueueGlob)) File.Delete(f);
 
             var firstAnonymousId = Identity.Get(_testDir);
             Assert.IsNotNull(firstAnonymousId, "first session should have minted an anonymousId");