feat: Unity MCP-Server Integration pro Session

Sessions können jetzt einen Unity MCP-Server (URL + Token) konfigurieren.
Die CLI erhält automatisch die MCP-Config mit korrektem Transport-Typ
(URL-basierte Erkennung: /sse → SSE, sonst HTTP für streamableHttp).

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

Endpoints/ChatEndpoint.cs

@@ -245,7 +245,7 @@ public static class ChatEndpoint
                 {
                     if (anthropic.IsCliAvailable)
                     {
-                        await anthropic.StreamChatViaCli(res, ctx.ModelId, ctx.SystemPrompt, messages, ctx.ChainId, workspace: ctx.Workspace, allowUserChoice: ctx.Agent?.AllowUserChoice ?? true, planMode: body.PlanMode, webSearch: !string.IsNullOrEmpty(ctx.WebSearchVersion), sessionId: sessionId, agentId: ctx.AgentId, remoteMgr: remoteMgr, workCt: workCt, sseCt: sseCt);
+                        await anthropic.StreamChatViaCli(res, ctx.ModelId, ctx.SystemPrompt, messages, ctx.ChainId, workspace: ctx.Workspace, allowUserChoice: ctx.Agent?.AllowUserChoice ?? true, planMode: body.PlanMode, webSearch: !string.IsNullOrEmpty(ctx.WebSearchVersion), sessionId: sessionId, agentId: ctx.AgentId, remoteMgr: remoteMgr, unityMcpUrl: ctx.Session?.UnityMcpUrl, unityMcpToken: ctx.Session?.UnityMcpToken, workCt: workCt, sseCt: sseCt);
                     }
                     else
                     {

Endpoints/SessionEndpoint.cs

@@ -80,6 +80,8 @@ public static class SessionEndpoint
                 s.MaxReviewIterations,
                 s.FinalizerAgentId,
                 s.PreparerAgentId,
+                s.UnityMcpUrl,
+                s.UnityMcpToken,
                 s.IsDeleted,
                 s.CreatedAt,
                 s.UpdatedAt,