feat(content-management): add create category page

- Creates new page for category creation
- Integrates with CreateCategoryBloc
- Handles form input and submission
- Displays success and error messages
- Refreshes category list on success

Author: fulleni

lib/content_management/view/create_category_page.dart

@@ -0,0 +1,151 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_bloc/flutter_bloc.dart';
+import 'package:go_router/go_router.dart';
+import 'package:ht_dashboard/content_management/bloc/content_management_bloc.dart';
+import 'package:ht_dashboard/content_management/bloc/create_category/create_category_bloc.dart';
+import 'package:ht_dashboard/l10n/l10n.dart';
+import 'package:ht_dashboard/shared/shared.dart';
+import 'package:ht_data_repository/ht_data_repository.dart';
+import 'package:ht_shared/ht_shared.dart';
+
+/// {@template create_category_page}
+/// A page for creating a new category.
+/// It uses a [BlocProvider] to create and provide a [CreateCategoryBloc].
+/// {@endtemplate}
+class CreateCategoryPage extends StatelessWidget {
+  /// {@macro create_category_page}
+  const CreateCategoryPage({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return BlocProvider(
+      create: (context) => CreateCategoryBloc(
+        categoriesRepository: context.read<HtDataRepository<Category>>(),
+      ),
+      child: const _CreateCategoryView(),
+    );
+  }
+}
+
+class _CreateCategoryView extends StatefulWidget {
+  const _CreateCategoryView();
+
+  @override
+  State<_CreateCategoryView> createState() => _CreateCategoryViewState();
+}
+
+class _CreateCategoryViewState extends State<_CreateCategoryView> {
+  final _formKey = GlobalKey<FormState>();
+
+  @override
+  Widget build(BuildContext context) {
+    final l10n = context.l10n;
+    return Scaffold(
+      appBar: AppBar(
+        title: Text(l10n.createCategory),
+        actions: [
+          BlocBuilder<CreateCategoryBloc, CreateCategoryState>(
+            builder: (context, state) {
+              if (state.status == CreateCategoryStatus.submitting) {
+                return const Padding(
+                  padding: EdgeInsets.only(right: AppSpacing.lg),
+                  child: SizedBox(
+                    width: 24,
+                    height: 24,
+                    child: CircularProgressIndicator(strokeWidth: 3),
+                  ),
+                );
+              }
+              return IconButton(
+                icon: const Icon(Icons.save),
+                tooltip: l10n.saveChanges,
+                onPressed: state.isFormValid
+                    ? () => context.read<CreateCategoryBloc>().add(
+                        const CreateCategorySubmitted(),
+                      )
+                    : null,
+              );
+            },
+          ),
+        ],
+      ),
+      body: BlocConsumer<CreateCategoryBloc, CreateCategoryState>(
+        listenWhen: (previous, current) => previous.status != current.status,
+        listener: (context, state) {
+          if (state.status == CreateCategoryStatus.success &&
+              ModalRoute.of(context)!.isCurrent) {
+            ScaffoldMessenger.of(context)
+              ..hideCurrentSnackBar()
+              ..showSnackBar(
+                SnackBar(
+                  content: Text(l10n.categoryCreatedSuccessfully),
+                ),
+              );
+            context.read<ContentManagementBloc>().add(
+              const LoadCategoriesRequested(),
+            );
+            context.pop();
+          }
+          if (state.status == CreateCategoryStatus.failure) {
+            ScaffoldMessenger.of(context)
+              ..hideCurrentSnackBar()
+              ..showSnackBar(
+                SnackBar(
+                  content: Text(state.errorMessage ?? l10n.unknownError),
+                  backgroundColor: Theme.of(context).colorScheme.error,
+                ),
+              );
+          }
+        },
+        builder: (context, state) {
+          return SingleChildScrollView(
+            child: Padding(
+              padding: const EdgeInsets.all(AppSpacing.lg),
+              child: Form(
+                key: _formKey,
+                child: Column(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  children: [
+                    TextFormField(
+                      initialValue: state.name,
+                      decoration: InputDecoration(
+                        labelText: l10n.categoryName,
+                        border: const OutlineInputBorder(),
+                      ),
+                      onChanged: (value) => context
+                          .read<CreateCategoryBloc>()
+                          .add(CreateCategoryNameChanged(value)),
+                    ),
+                    const SizedBox(height: AppSpacing.lg),
+                    TextFormField(
+                      initialValue: state.description,
+                      decoration: InputDecoration(
+                        labelText: l10n.description,
+                        border: const OutlineInputBorder(),
+                      ),
+                      maxLines: 3,
+                      onChanged: (value) => context
+                          .read<CreateCategoryBloc>()
+                          .add(CreateCategoryDescriptionChanged(value)),
+                    ),
+                    const SizedBox(height: AppSpacing.lg),
+                    TextFormField(
+                      initialValue: state.iconUrl,
+                      decoration: InputDecoration(
+                        labelText: l10n.iconUrl,
+                        border: const OutlineInputBorder(),
+                      ),
+                      onChanged: (value) => context
+                          .read<CreateCategoryBloc>()
+                          .add(CreateCategoryIconUrlChanged(value)),
+                    ),
+                  ],
+                ),
+              ),
+            ),
+          );
+        },
+      ),
+    );
+  }
+}