Agent does not handle SignalR client-side upgrade issues

### Description

Direct customer feedback:

> SignalR failed to initialize at runtime after upgrading an ASP.NET MVC application. Root cause: pace.js (bundled in Vendors.bundle.js) overrides the native WebSocket, disrupting SignalR's handshake. The agent assumed the problem was server-side and attempted server-side fixes unsuccessfully. Only when explicitly told the issue was client-side did the model identify the correct root cause.

Expected Behavior:

The agent should check for known client-side conflicts during SignalR upgrades (e.g., third-party scripts overriding WebSocket) and apply the appropriate fix pattern (save/restore native WebSocket before loading conflicting scripts).

Additional Context:

The Opus model only identifies the real root cause (client-side pace.js) when explicitly informed the issue is on the client side. Without that hint, it loops on server-side fixes. This suggests a diagnostic gap in how the agent reasons about SignalR failures.