refactor: convert library scan to Server Action

- Add src/app/actions/library.ts with scanLibrary
- Update ScanButton to use Server Action
- Remove POST from api/komga/libraries/[libraryId]/scan route

src/app/api/komga/libraries/[libraryId]/scan/route.ts

@@ -1,45 +0,0 @@
-import { NextResponse } from "next/server";
-import { LibraryService } from "@/lib/services/library.service";
-import { ERROR_CODES } from "@/constants/errorCodes";
-import { AppError } from "@/utils/errors";
-import { getErrorMessage } from "@/utils/errors";
-import type { NextRequest } from "next/server";
-import logger from "@/lib/logger";
-
-export async function POST(
-  request: NextRequest,
-  { params }: { params: Promise<{ libraryId: string }> }
-) {
-  try {
-    const libraryId: string = (await params).libraryId;
-
-    // Scan library with deep=false
-    await LibraryService.scanLibrary(libraryId, false);
-
-    return NextResponse.json({ success: true });
-  } catch (error) {
-    logger.error({ err: error }, "API Library Scan - Erreur");
-    if (error instanceof AppError) {
-      return NextResponse.json(
-        {
-          error: {
-            code: error.code,
-            name: "Library scan error",
-            message: getErrorMessage(error.code),
-          },
-        },
-        { status: 500 }
-      );
-    }
-    return NextResponse.json(
-      {
-        error: {
-          code: ERROR_CODES.LIBRARY.SCAN_ERROR,
-          name: "Library scan error",
-          message: getErrorMessage(ERROR_CODES.LIBRARY.SCAN_ERROR),
-        },
-      },
-      { status: 500 }
-    );
-  }
-}