Add configuration files and update project documentation

- Introduced .editorconfig for consistent coding styles across the project.
- Added .golangci.yml for Go linting configuration.
- Updated AGENTS.md to clarify project structure and components.
- Enhanced CONTRIBUTING.md with Makefile usage for common tasks.
- Updated Dockerfiles to use Go 1.24 and improved build instructions.
- Refined README.md and deployment documentation for clarity.
- Added testing documentation in testing.md for backend and frontend tests.
- Introduced Makefile for streamlined development commands and tasks.

frontend-nuxt/pages/admin/users/[username].vue

@@ -3,31 +3,31 @@
     <h1 class="text-2xl font-bold mb-6">{{ isNew ? 'New user' : `Edit ${username}` }}</h1>
 
     <form @submit.prevent="submit" class="flex flex-col gap-4">
-      <div class="form-control">
+      <fieldset class="fieldset">
         <label class="label" for="user">Username</label>
         <input
           id="user"
           v-model="form.user"
           type="text"
-          class="input input-bordered"
+          class="input"
           required
           :readonly="!isNew"
         />
-      </div>
+      </fieldset>
       <PasswordInput
         v-model="form.pass"
         label="Password (leave blank to keep)"
         autocomplete="new-password"
       />
-      <div class="form-control">
+      <fieldset class="fieldset">
         <label class="label">Auths</label>
         <div class="flex flex-wrap gap-2">
           <label v-for="a of authOptions" :key="a" class="label cursor-pointer gap-2" :for="`auth-${a}`">
             <input :id="`auth-${a}`" v-model="form.auths" type="checkbox" :value="a" class="checkbox checkbox-sm" />
-            <span class="label-text">{{ a }}</span>
+            <span>{{ a }}</span>
           </label>
         </div>
-      </div>
+      </fieldset>
       <p v-if="error" class="text-error text-sm">{{ error }}</p>
       <div class="flex gap-2">
         <button type="submit" class="btn btn-primary" :disabled="loading">