feat: implement server-side NativeStorageService for browser storage interoperability

src/NexusReader.Web.New/Services/NativeStorageService.cs

@@ -0,0 +1,82 @@
+using FluentResults;
+using Microsoft.JSInterop;
+using NexusReader.Application.Abstractions.Services;
+
+namespace NexusReader.Web.New.Services;
+
+/// <summary>
+/// Server-side implementation of INativeStorageService for Blazor Server.
+/// Uses JS Interop to access browser local storage.
+/// </summary>
+public class NativeStorageService : INativeStorageService
+{
+    private readonly IJSRuntime _jsRuntime;
+
+    public NativeStorageService(IJSRuntime jsRuntime)
+    {
+        _jsRuntime = jsRuntime;
+    }
+
+    public async Task<Result<string>> GetSecureString(string key)
+    {
+        try
+        {
+            var value = await _jsRuntime.InvokeAsync<string>("localStorage.getItem", key);
+            return Result.Ok(value ?? string.Empty);
+        }
+        catch (Exception ex)
+        {
+            return Result.Fail(new Error("Failed to read from local storage").CausedBy(ex));
+        }
+    }
+
+    public async Task<Result> SaveSecureString(string key, string value)
+    {
+        try
+        {
+            await _jsRuntime.InvokeVoidAsync("localStorage.setItem", key, value);
+            return Result.Ok();
+        }
+        catch (Exception ex)
+        {
+            return Result.Fail(new Error("Failed to write to local storage").CausedBy(ex));
+        }
+    }
+
+    public async Task<Result<bool>> GetBool(string key)
+    {
+        var result = await GetSecureString(key);
+        if (result.IsFailed) return Result.Fail(result.Errors);
+        return Result.Ok(bool.TryParse(result.Value, out var val) && val);
+    }
+
+    public async Task<Result> SaveBool(string key, bool value)
+    {
+        return await SaveSecureString(key, value.ToString().ToLower());
+    }
+
+    public async Task<Result<int>> GetInt(string key)
+    {
+        var result = await GetSecureString(key);
+        if (result.IsFailed) return Result.Fail(result.Errors);
+        return Result.Ok(int.TryParse(result.Value, out var val) ? val : 0);
+    }
+
+    public async Task<Result> SaveInt(string key, int value)
+    {
+        return await SaveSecureString(key, value.ToString());
+    }
+
+    public async Task<Result> ClearAll()
+    {
+        try
+        {
+            await _jsRuntime.InvokeVoidAsync("localStorage.clear");
+            return Result.Ok();
+        }
+        catch (Exception ex)
+        {
+            return Result.Fail(new Error("Failed to clear local storage").CausedBy(ex));
+        }
+    }
+}