feat(guild): breakup + emblem_list + others_info

Implements GuildService.BreakupAsync (soft-delete guild, hard-delete
dependents, clear viewer GuildId pointers). Wires /guild/breakup,
/guild/emblem_list, /guild/others_info in GuildController. Fixes
ToDetailDto to accept and populate leader_name from the member list.
Adds GuildServiceBreakupTests (3 tests: cascade delete, permission
guard, leader_name HTTP regression).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

SVSim.UnitTests/Services/Guild/GuildServiceBreakupTests.cs

@@ -0,0 +1,152 @@
+using System.Net.Http.Json;
+using System.Text;
+using System.Text.Json;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.DependencyInjection;
+using SVSim.Database;
+using SVSim.Database.Entities.Guild;
+using SVSim.Database.Services.Guild;
+using SVSim.UnitTests.Infrastructure;
+
+namespace SVSim.UnitTests.Services.Guild;
+
+public class GuildServiceBreakupTests
+{
+    private const string BaseReq = """{"viewer_id":"0","steam_id":0,"steam_session_ticket":""}""";
+
+    [Test]
+    public async Task BreakupAsync_soft_deletes_guild_and_cascade_hard_deletes_dependents()
+    {
+        using var factory = new SVSimTestFactory();
+        var leaderId = await factory.SeedViewerAsync(76_561_198_100_000_010UL, "BreakupLeader");
+        var memberId = await factory.SeedViewerAsync(76_561_198_100_000_011UL, "BreakupMember");
+
+        int guildId;
+
+        // Create the guild as leader.
+        using (var scope = factory.Services.CreateScope())
+        {
+            var svc = scope.ServiceProvider.GetRequiredService<IGuildService>();
+            var res = await svc.CreateAsync(leaderId, new("BreakupGuild", (int)GuildActivity.All, (int)GuildJoinCondition.Free));
+            Assert.That(res.IsOk, Is.True);
+            guildId = res.GuildId!.Value;
+        }
+
+        // Add member2 directly via DbContext (simulates a later join).
+        using (var scope = factory.Services.CreateScope())
+        {
+            var db = scope.ServiceProvider.GetRequiredService<SVSimDbContext>();
+            db.GuildMembers.Add(new GuildMember
+            {
+                GuildId = guildId,
+                ViewerId = memberId,
+                Role = GuildRole.Regular,
+                JoinedAt = DateTime.UtcNow,
+            });
+            var viewer = await db.Viewers.FirstAsync(v => v.Id == memberId);
+            viewer.GuildId = guildId;
+            await db.SaveChangesAsync();
+        }
+
+        // Breakup as leader.
+        using (var scope = factory.Services.CreateScope())
+        {
+            var svc = scope.ServiceProvider.GetRequiredService<IGuildService>();
+            var res = await svc.BreakupAsync(leaderId);
+            Assert.That(res.IsOk, Is.True);
+        }
+
+        // Assert: guild has BreakupAt set.
+        using (var scope = factory.Services.CreateScope())
+        {
+            var db = scope.ServiceProvider.GetRequiredService<SVSimDbContext>();
+
+            var guild = await db.Guilds.FirstOrDefaultAsync(g => g.GuildId == guildId);
+            Assert.That(guild, Is.Not.Null, "Guild row should still exist (soft-delete)");
+            Assert.That(guild!.BreakupAt, Is.Not.Null, "BreakupAt must be set");
+
+            // 0 members remain.
+            var memberCount = await db.GuildMembers.CountAsync(m => m.GuildId == guildId);
+            Assert.That(memberCount, Is.EqualTo(0), "All GuildMember rows must be hard-deleted");
+
+            // Both viewers' GuildId is null.
+            var leaderViewer = await db.Viewers.FirstAsync(v => v.Id == leaderId);
+            var memberViewer = await db.Viewers.FirstAsync(v => v.Id == memberId);
+            Assert.That(leaderViewer.GuildId, Is.Null, "Leader's GuildId should be cleared");
+            Assert.That(memberViewer.GuildId, Is.Null, "Member's GuildId should be cleared");
+        }
+    }
+
+    [Test]
+    public async Task BreakupAsync_returns_PermissionDenied_for_non_leader()
+    {
+        using var factory = new SVSimTestFactory();
+        var leaderId = await factory.SeedViewerAsync(76_561_198_100_000_012UL, "NLLeader");
+        var memberId = await factory.SeedViewerAsync(76_561_198_100_000_013UL, "NLMember");
+
+        int guildId;
+        using (var scope = factory.Services.CreateScope())
+        {
+            var svc = scope.ServiceProvider.GetRequiredService<IGuildService>();
+            var res = await svc.CreateAsync(leaderId, new("NLGuild", (int)GuildActivity.All, (int)GuildJoinCondition.Free));
+            Assert.That(res.IsOk, Is.True);
+            guildId = res.GuildId!.Value;
+        }
+
+        // Directly add member.
+        using (var scope = factory.Services.CreateScope())
+        {
+            var db = scope.ServiceProvider.GetRequiredService<SVSimDbContext>();
+            db.GuildMembers.Add(new GuildMember
+            {
+                GuildId = guildId,
+                ViewerId = memberId,
+                Role = GuildRole.Regular,
+                JoinedAt = DateTime.UtcNow,
+            });
+            var viewer = await db.Viewers.FirstAsync(v => v.Id == memberId);
+            viewer.GuildId = guildId;
+            await db.SaveChangesAsync();
+        }
+
+        // Non-leader tries to break up.
+        using (var scope = factory.Services.CreateScope())
+        {
+            var svc = scope.ServiceProvider.GetRequiredService<IGuildService>();
+            var res = await svc.BreakupAsync(memberId);
+            Assert.That(res.Code, Is.EqualTo(GuildOpResultCode.PermissionDenied));
+        }
+    }
+
+    [Test]
+    public async Task GuildInfo_JOINING_response_populates_leader_name()
+    {
+        using var factory = new SVSimTestFactory();
+        var viewerId = await factory.SeedViewerAsync(76_561_198_100_000_014UL, "LeaderDisplayName");
+
+        // Create guild.
+        using (var scope = factory.Services.CreateScope())
+        {
+            var svc = scope.ServiceProvider.GetRequiredService<IGuildService>();
+            var res = await svc.CreateAsync(viewerId, new("LeaderNameGuild", (int)GuildActivity.All, (int)GuildJoinCondition.Free));
+            Assert.That(res.IsOk, Is.True);
+        }
+
+        // Hit /guild/info via HTTP (middleware is no-op in test mode — no UnityPlayer UA).
+        using var client = factory.CreateAuthenticatedClient(viewerId);
+        var resp = await client.PostAsync("/guild/info",
+            new StringContent(BaseReq, Encoding.UTF8, "application/json"));
+        var body = await resp.Content.ReadAsStringAsync();
+        Assert.That(resp.IsSuccessStatusCode, Is.True, $"guild/info failed: {body}");
+
+        using var doc = JsonDocument.Parse(body);
+        var leaderName = doc.RootElement
+            .GetProperty("guild")
+            .GetProperty("detail")
+            .GetProperty("leader_name")
+            .GetString();
+
+        Assert.That(leaderName, Is.EqualTo("LeaderDisplayName"),
+            "leader_name in guild/info detail must equal the viewer's display name");
+    }
+}