♻️ Remove the discovery service in the Sphere.

DysonNetwork.Pass/Realm/RealmDiscoveryController.cs

@@ -0,0 +1,37 @@
+using DysonNetwork.Shared.Models;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.EntityFrameworkCore;
+
+namespace DysonNetwork.Pass.Realm;
+
+[ApiController]
+[Route("api/realms/discovery")]
+public class RealmDiscoveryController(AppDatabase db) : ControllerBase
+{
+    [HttpGet]
+    public async Task<ActionResult<List<SnRealm>>> GetRealmDiscovery(
+        [FromQuery] string? query,
+        [FromQuery] int take = 10,
+        [FromQuery] int offset = 0
+    )
+    {
+        var realmsQuery = db.Realms
+            .Where(r => r.IsCommunity)
+            .OrderByDescending(r => r.Members.Count)
+            .AsQueryable();
+        if (!string.IsNullOrWhiteSpace(query))
+            realmsQuery = realmsQuery.Where(r =>
+                EF.Functions.ILike(r.Name, $"%{query}%") ||
+                EF.Functions.ILike(r.Description, $"%{query}%")
+            );
+
+        var totalCount = await realmsQuery.CountAsync();
+        Response.Headers["X-Total"] = totalCount.ToString();
+
+        var realms = await realmsQuery
+            .Take(take)
+            .Skip(offset)
+            .ToListAsync();
+        return Ok(realms);
+    }
+}