fix: disable redirect to trailing slashes (#89)

Starlette's default behavior adds a trailing slash to every routes
without it (https://github.com/encode/starlette/discussions/2548), e.g.
when client initiates a request to `/mcp`, it returns a `307 Temporary
Redirect` response to `/mcp/`. This is causing some annoying issues,
especially in our internal environment where server instances sit behind
a load balancer and do not have access to their actual domain name,
Starlette returns the instance's internal ip which the client cannot
recognize and access. This PR disables this behavior.

Signed-off-by: Jianxin Qiu <jianxin.qiu@outlook.com>

src/mcp_proxy/mcp_server.py

@@ -185,6 +185,8 @@ async def run_mcp_server(
             lifespan=combined_lifespan,
         )
 
+        starlette_app.router.redirect_slashes = False
+
         config = uvicorn.Config(
             starlette_app,
             host=mcp_settings.bind_host,