Added Search function for items and fixed javascript controller

app/controllers/items_controller.rb

@@ -5,6 +5,15 @@ class ItemsController < ApplicationController
   def index
     @items = Item.all.includes(:category, :user, :room).order(created_at: :desc)
 
+    if params[:query].present?
+      query_str = "%#{params[:query]}%"
+      # Durchsucht Name, SKU, Seriennummer und deine Sticker-ID gleichzeitig
+      @items = @items.where(
+        "items.name LIKE :q OR items.sku LIKE :q OR items.serial_number LIKE :q OR items.sticker_id LIKE :q",
+        q: query_str
+      )
+    end
+
     respond_to do |format|
     format.html # Rendert ganz normal deine Bestandsliste im Browser
     format.csv do