feat(api): playout read endpoints + reset-all (#100 #101 #107 #110)

- GET /api/playouts — paged list over GetPagedPlayouts (query/pageNum/pageSize), list DTO with buildStatus (#100, #107)
- GET /api/playouts/{id}/items — paged future items + UNSCHEDULED gaps over GetFuturePlayoutItemsById; 404 ProblemDetails for unknown playout (matches /api/schedules/{id}/items precedent) (#101)
- buildStatus {lastBuild, success, message} on GET /api/playouts/{id} (BuildStatus now included by GetPlayoutByIdHandler) (#107)
- GET /api/playouts/warnings/count — failed-build count for the warnings badge (#107)
- POST /api/playouts/reset-all — 202 Accepted, wraps ResetAllPlayouts (#110)
- POST /api/channels/{channelNumber}/playout/reset — optional ?mode= override; default branches by ScheduleKind (Classic→Refresh, others→Reset) to match Blazor semantics (#110)
- Option<FillerKind>→FillerKind? projection uses MatchUnsafe (Match throws on null-returning branch; idiom per Health/Mapper.cs)
- Tests: controller unit tests (routes, projections, 404s, reset-mode defaults), OpenAPI ProblemDetails contract entry for /api/playouts/{id}/items get 404
- Regenerated wwwroot/openapi/v1.json

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

ErsatzTV.Core/Api/Playouts/PagedPlayoutItemsResponseModel.cs

@@ -0,0 +1,5 @@
+namespace ErsatzTV.Core.Api.Playouts;
+
+public record PagedPlayoutItemsResponseModel(
+    int TotalCount,
+    List<PlayoutItemResponseModel> Page);

ErsatzTV.Core/Api/Playouts/PagedPlayoutsResponseModel.cs

@@ -0,0 +1,5 @@
+namespace ErsatzTV.Core.Api.Playouts;
+
+public record PagedPlayoutsResponseModel(
+    int TotalCount,
+    List<PlayoutListItemResponseModel> Page);

ErsatzTV.Core/Api/Playouts/PlayoutBuildStatusResponseModel.cs

@@ -0,0 +1,6 @@
+namespace ErsatzTV.Core.Api.Playouts;
+
+public record PlayoutBuildStatusResponseModel(
+    DateTimeOffset LastBuild,
+    bool Success,
+    string Message);

ErsatzTV.Core/Api/Playouts/PlayoutItemResponseModel.cs

@@ -0,0 +1,10 @@
+using ErsatzTV.Core.Domain.Filler;
+
+namespace ErsatzTV.Core.Api.Playouts;
+
+public record PlayoutItemResponseModel(
+    string Title,
+    DateTimeOffset Start,
+    DateTimeOffset Finish,
+    string Duration,
+    FillerKind? FillerKind);

ErsatzTV.Core/Api/Playouts/PlayoutListItemResponseModel.cs

@@ -0,0 +1,13 @@
+#nullable enable
+using ErsatzTV.Core.Domain;
+
+namespace ErsatzTV.Core.Api.Playouts;
+
+public record PlayoutListItemResponseModel(
+    int Id,
+    string ChannelNumber,
+    string ChannelName,
+    PlayoutScheduleKind ScheduleKind,
+    string ScheduleName,
+    TimeSpan? DailyRebuildTime,
+    PlayoutBuildStatusResponseModel? BuildStatus);

ErsatzTV.Core/Api/Playouts/PlayoutResponseModel.cs

@@ -1,3 +1,4 @@
+#nullable enable
 using ErsatzTV.Core.Domain;
 
 namespace ErsatzTV.Core.Api.Playouts;
@@ -9,8 +10,9 @@ public record PlayoutResponseModel(
     string ChannelNumber,
     ChannelPlayoutMode PlayoutMode,
     string ScheduleName,
-    string ScheduleFile,
-    TimeSpan? DailyRebuildTime)
+    string? ScheduleFile,
+    TimeSpan? DailyRebuildTime,
+    PlayoutBuildStatusResponseModel? BuildStatus)
 {
     public static PlayoutResponseModel From(
         int id,
@@ -19,8 +21,9 @@ public record PlayoutResponseModel(
         string channelNumber,
         ChannelPlayoutMode playoutMode,
         string scheduleName,
-        string scheduleFile,
-        TimeSpan? dailyRebuildTime) =>
+        string? scheduleFile,
+        TimeSpan? dailyRebuildTime,
+        PlayoutBuildStatusResponseModel? buildStatus) =>
         new(
             id,
             scheduleKind,
@@ -29,5 +32,6 @@ public record PlayoutResponseModel(
             playoutMode,
             scheduleName,
             scheduleFile,
-            dailyRebuildTime);
+            dailyRebuildTime,
+            buildStatus);
 }