fix: invert reversed storage guard condition in MP4 finalization

The ternary in GetLowStoragePauseMessageAsync had its branches swapped:
when storage was healthy it returned the pause error, and when storage
was critically low it returned null (allowing finalization to proceed).
This caused MP4 finalization to always pause with a misleading 'storage
is Red' warning even when storage protection was disabled.

docker-compose.yml

@@ -16,7 +16,13 @@ services:
       start_period: 10s
 
   api:
-    image: ${REGISTRY_URL:-reg.nxsir.cn}/live_recorder/app-api:latest
+    build:
+      context: .
+      dockerfile: src/LiveRecorder.WebApi/Dockerfile
+      network: host
+      args:
+        DOTNET_SDK_IMAGE: ${DOTNET_SDK_IMAGE:-mcr.microsoft.com/dotnet/sdk:8.0-bookworm-slim}
+        DOTNET_RUNTIME_IMAGE: ${DOTNET_RUNTIME_IMAGE:-mcr.microsoft.com/dotnet/aspnet:8.0-bookworm-slim}
     restart: unless-stopped
     depends_on:
       postgres:
@@ -32,7 +38,14 @@ services:
       - "8080"
 
   nginx:
-    image: ${REGISTRY_URL:-reg.nxsir.cn}/live_recorder/app-web:latest
+    build:
+      context: ./frontend
+      dockerfile: Dockerfile
+      network: host
+      args:
+        NODE_IMAGE: ${NODE_IMAGE:-node:22-alpine}
+        NGINX_IMAGE: ${NGINX_IMAGE:-nginx:1.27-alpine}
+        VITE_API_BASE_URL: /api
     restart: unless-stopped
     depends_on:
       - api

src/LiveRecorder.Infrastructure/Services/FfmpegService.Utils.cs

@@ -50,8 +50,8 @@ public sealed partial class FfmpegService
             var sourceSizeBytes = new FileInfo(sourcePath).Length;
             var storageCheck = _storageGuardService.CheckCanStartOrResume(settings, sourceSizeBytes);
             return storageCheck.ShouldPauseActive
-                ? null
-                : $"{LowStoragePauseErrorPrefix} {storageCheck.Message}";
+                ? $"{LowStoragePauseErrorPrefix} {storageCheck.Message}"
+                : null;
         }
 
         var lowStoragePauseMessage = await GetLowStoragePauseMessageAsync();