feat: add cache size retrieval functionality and display in CacheSettings component

src/app/api/komga/cache/size/route.ts

@@ -0,0 +1,31 @@
+import { NextResponse } from "next/server";
+import type { ServerCacheService } from "@/lib/services/server-cache.service";
+import { getServerCacheService } from "@/lib/services/server-cache.service";
+import { ERROR_CODES } from "@/constants/errorCodes";
+import { getErrorMessage } from "@/utils/errors";
+
+export async function GET() {
+  try {
+    const cacheService: ServerCacheService = await getServerCacheService();
+    const { sizeInBytes, itemCount } = await cacheService.getCacheSize();
+    
+    return NextResponse.json({ 
+      sizeInBytes, 
+      itemCount,
+      mode: cacheService.getCacheMode()
+    });
+  } catch (error) {
+    console.error("Erreur lors de la récupération de la taille du cache:", error);
+    return NextResponse.json(
+      {
+        error: {
+          code: ERROR_CODES.CACHE.SIZE_FETCH_ERROR,
+          name: "Cache size fetch error",
+          message: getErrorMessage(ERROR_CODES.CACHE.SIZE_FETCH_ERROR),
+        },
+      },
+      { status: 500 }
+    );
+  }
+}
+