Database-level multi-library support #48 (#58)

* feat: start of library backends

* feat: update backend routes and create initializer

* feat: add legacy library creation

* fix: resolve frontend type errors

* fix: runtime errors

* fix: lint

prisma/models/app.prisma

@@ -1,7 +1,7 @@
 model ApplicationSettings {
     timestamp DateTime @id @default(now())
 
-    metadataProviders             String[]
+    metadataProviders String[]
 
     saveSlotCountLimit   Int   @default(5)
     saveSlotSizeLimit    Float @default(10) // MB
@@ -13,3 +13,17 @@ enum Platform {
     Linux   @map("linux")
     macOS   @map("macos")
 }
+
+enum LibraryBackend {
+    Filesystem
+}
+
+model Library {
+    id   String @id @default(uuid())
+    name String
+
+    backend LibraryBackend
+    options Json
+
+    games    Game[]
+}