Per-server MCP connect timeout; stuck approval prompts fixed

New features

• Per-server MCP connect timeout - MCP server configs accept a connectTimeout so a slow-starting server gets more time to connect instead of failing at startup

Bug fixes

• Stuck approval prompts - An approval prompt no longer stays wedged when the request behind it is already gone, so Enter and Esc respond again
• Spec mode message color - Messages you send in spec mode keep the spec color when the view repaints or you resume the session, instead of looking like a normal turn
• Sign-in with multiple windows - Sign-in and MCP authorization now finish in the window that started them instead of hanging when more than one window is open (app)
• File diff animations - Opening and closing a file diff animates again instead of snapping into place (app)