fix: use correct Kapa MCP base URL (remove /sse path)

The Kapa MCP server uses OAuth authentication at the base URL, not
an SSE endpoint at /sse. Remove the incorrect path and transport field.

Co-Authored-By: Oz <oz-agent@warp.dev>

Author: rachaelrenk

public/.well-known/mcp.json

@@ -1,6 +1,5 @@
 {
   "name": "Warp Documentation",
   "description": "Search and retrieve Warp documentation — the agentic development environment and Oz, Warp's programmable agent platform.",
-  "url": "https://warp.mcp.kapa.ai/sse",
-  "transport": "sse"
+  "url": "https://warp.mcp.kapa.ai"
 }