refactor(audience-sample): centralise custom demo property keys in SampleAppCustomEventPropertyKeys

The sample-app demo catalogue, screen_viewed Track call, and the
typed-event live-fire tests had property keys (method, source,
gameId, platform, gameName, slug, url, label, path) inline at every
call site. Each key duplicates between the catalogue's EventField
definition and the live-fire test's UI lookup.

Add SampleAppCustomEventPropertyKeys alongside SampleAppCustomEvents
(mirrors the SDK's EventPropertyKeys naming) and reference the
constants from AudienceSample.Events.cs, AudienceSample.cs (the
screen_viewed props dictionary), and SampleAppLiveFireTests.cs (the
TypedEventField field-name lookups).

Includes gameName and slug beyond the user's listed seven keys: same
inline-property-key category, same migration treatment.

Per the user's "everything random goes in a constant" stance,
applied against the previous session's recommendation that the demo
content read better inline. Recording the override on the user's
explicit request.

Follow-up to SDK-272 (centralisation of duplicated literals).

Author: ImmutableJeffrey

examples/audience/Assets/SampleApp/Scripts/AudienceSample.Events.cs

@@ -55,15 +55,15 @@ internal readonly struct EventSpec
 
         internal static readonly EventSpec[] Catalogue =
         {
-            new EventSpec(SampleAppCustomEvents.SignUp,        new[] { EventField.Text("method", optional: true) }),
-            new EventSpec(SampleAppCustomEvents.SignIn,        new[] { EventField.Text("method", optional: true) }),
-            new EventSpec(SampleAppCustomEvents.EmailAcquired, new[] { EventField.Text("source", optional: true) }),
+            new EventSpec(SampleAppCustomEvents.SignUp,        new[] { EventField.Text(SampleAppCustomEventPropertyKeys.Method, optional: true) }),
+            new EventSpec(SampleAppCustomEvents.SignIn,        new[] { EventField.Text(SampleAppCustomEventPropertyKeys.Method, optional: true) }),
+            new EventSpec(SampleAppCustomEvents.EmailAcquired, new[] { EventField.Text(SampleAppCustomEventPropertyKeys.Source, optional: true) }),
             new EventSpec(SampleAppCustomEvents.WishlistAdd,   new[] {
-                EventField.Text("gameId"),
-                EventField.Text("source",   optional: true),
-                EventField.Text("platform", optional: true),
+                EventField.Text(SampleAppCustomEventPropertyKeys.GameId),
+                EventField.Text(SampleAppCustomEventPropertyKeys.Source,   optional: true),
+                EventField.Text(SampleAppCustomEventPropertyKeys.Platform, optional: true),
             }),
-            new EventSpec(SampleAppCustomEvents.WishlistRemove, new[] { EventField.Text("gameId") }),
+            new EventSpec(SampleAppCustomEvents.WishlistRemove, new[] { EventField.Text(SampleAppCustomEventPropertyKeys.GameId) }),
             new EventSpec(EventNames.Purchase, new[] {
                 EventField.Text(EventPropertyKeys.Currency),
                 EventField.Number(EventPropertyKeys.Value),
@@ -92,15 +92,15 @@ internal readonly struct EventSpec
             }),
             new EventSpec(EventNames.MilestoneReached, new[] { EventField.Text(EventPropertyKeys.Name) }),
             new EventSpec(SampleAppCustomEvents.GamePageViewed,  new[] {
-                EventField.Text("gameId"),
-                EventField.Text("gameName", optional: true),
-                EventField.Text("slug",     optional: true),
+                EventField.Text(SampleAppCustomEventPropertyKeys.GameId),
+                EventField.Text(SampleAppCustomEventPropertyKeys.GameName, optional: true),
+                EventField.Text(SampleAppCustomEventPropertyKeys.Slug,     optional: true),
             }),
             new EventSpec(SampleAppCustomEvents.LinkClicked, new[] {
-                EventField.Text("url"),
-                EventField.Text("label",  optional: true),
-                EventField.Text("source", optional: true),
-                EventField.Text("gameId", optional: true),
+                EventField.Text(SampleAppCustomEventPropertyKeys.Url),
+                EventField.Text(SampleAppCustomEventPropertyKeys.Label,  optional: true),
+                EventField.Text(SampleAppCustomEventPropertyKeys.Source, optional: true),
+                EventField.Text(SampleAppCustomEventPropertyKeys.GameId, optional: true),
             }),
         };
 

examples/audience/Assets/SampleApp/Scripts/AudienceSample.cs

@@ -110,7 +110,7 @@ private void OnPage() => RunAndLog(SampleAppUi.LogLabels.Page, () =>
         {
             GuardConsentForTrack();
             var screen = SceneManager.GetActiveScene().name;
-            var props = new Dictionary<string, object> { ["path"] = screen };
+            var props = new Dictionary<string, object> { [SampleAppCustomEventPropertyKeys.Path] = screen };
             ImmutableAudience.Track(SampleAppCustomEvents.ScreenViewed, props);
             return Json.Serialize(props, 2);
         });

examples/audience/Assets/SampleApp/Scripts/SampleAppCustomEvents.cs

@@ -12,4 +12,18 @@ internal static class SampleAppCustomEvents
         internal const string LinkClicked = "link_clicked";
         internal const string ScreenViewed = "screen_viewed";
     }
+
+    // Property keys for the sample-app demo events.
+    internal static class SampleAppCustomEventPropertyKeys
+    {
+        internal const string Method = "method";
+        internal const string Source = "source";
+        internal const string GameId = "gameId";
+        internal const string Platform = "platform";
+        internal const string GameName = "gameName";
+        internal const string Slug = "slug";
+        internal const string Url = "url";
+        internal const string Label = "label";
+        internal const string Path = "path";
+    }
 }

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

@@ -423,7 +423,7 @@ public IEnumerator TypedEvent_WishlistAdd_FlushReportsOk()
         {
             yield return DriveTypedEventAndFlush(SampleAppUi.Buttons.TypedEvent(SampleAppCustomEvents.WishlistAdd), root =>
             {
-                root.Q<TextField>(SampleAppUi.TypedEventField(SampleAppCustomEvents.WishlistAdd, "gameId")).value = "il2cpp_game_1";
+                root.Q<TextField>(SampleAppUi.TypedEventField(SampleAppCustomEvents.WishlistAdd, SampleAppCustomEventPropertyKeys.GameId)).value = "il2cpp_game_1";
             });
         }
 
@@ -432,7 +432,7 @@ public IEnumerator TypedEvent_WishlistRemove_FlushReportsOk()
         {
             yield return DriveTypedEventAndFlush(SampleAppUi.Buttons.TypedEvent(SampleAppCustomEvents.WishlistRemove), root =>
             {
-                root.Q<TextField>(SampleAppUi.TypedEventField(SampleAppCustomEvents.WishlistRemove, "gameId")).value = "il2cpp_game_1";
+                root.Q<TextField>(SampleAppUi.TypedEventField(SampleAppCustomEvents.WishlistRemove, SampleAppCustomEventPropertyKeys.GameId)).value = "il2cpp_game_1";
             });
         }
 
@@ -441,7 +441,7 @@ public IEnumerator TypedEvent_GamePageViewed_FlushReportsOk()
         {
             yield return DriveTypedEventAndFlush(SampleAppUi.Buttons.TypedEvent(SampleAppCustomEvents.GamePageViewed), root =>
             {
-                root.Q<TextField>(SampleAppUi.TypedEventField(SampleAppCustomEvents.GamePageViewed, "gameId")).value = "il2cpp_game_1";
+                root.Q<TextField>(SampleAppUi.TypedEventField(SampleAppCustomEvents.GamePageViewed, SampleAppCustomEventPropertyKeys.GameId)).value = "il2cpp_game_1";
             });
         }
 
@@ -450,7 +450,7 @@ public IEnumerator TypedEvent_LinkClicked_FlushReportsOk()
         {
             yield return DriveTypedEventAndFlush(SampleAppUi.Buttons.TypedEvent(SampleAppCustomEvents.LinkClicked), root =>
             {
-                root.Q<TextField>(SampleAppUi.TypedEventField(SampleAppCustomEvents.LinkClicked, "url")).value = "https://example.com/il2cpp";
+                root.Q<TextField>(SampleAppUi.TypedEventField(SampleAppCustomEvents.LinkClicked, SampleAppCustomEventPropertyKeys.Url)).value = "https://example.com/il2cpp";
             });
         }