Repoint tests and examples off removed deprecations

Replaces FastMCP.as_proxy() helper calls with create_proxy(), rewrites the
mount() as_proxy=/prefix= kwarg tests to plain mount() (the params are gone),
and deletes deprecation-only tests for as_proxy() and remove_tool().

examples/in_memory_proxy_example.py

@@ -3,7 +3,7 @@ This example demonstrates how to set up and use an in-memory FastMCP proxy.
 
 It illustrates the pattern:
 1. Create an original FastMCP server with some tools.
-2. Create a proxy FastMCP server using ``FastMCP.as_proxy(original_server)``.
+2. Create a proxy FastMCP server using ``create_proxy(original_server)``.
 3. Use another Client to connect to the proxy server (in-memory) and interact with the original server's tools through the proxy.
 """
 
@@ -13,6 +13,7 @@ from mcp.types import TextContent
 
 from fastmcp import FastMCP
 from fastmcp.client import Client
+from fastmcp.server import create_proxy
 
 
 class EchoService:
@@ -38,9 +39,9 @@ async def main():
     # 2. Proxy Server Creation
     print("\nStep 2: Creating the Proxy Server (InMemoryProxy)...")
     print(
-        f"          (Using FastMCP.as_proxy to wrap '{original_server.name}' directly)"
+        f"          (Using create_proxy to wrap '{original_server.name}' directly)"
     )
-    proxy_server = FastMCP.as_proxy(original_server, name="InMemoryProxy")
+    proxy_server = create_proxy(original_server, name="InMemoryProxy")
     print(
         f"   -> Proxy Server '{proxy_server.name}' created, proxying '{original_server.name}'."
     )

examples/mount_example.py

@@ -63,9 +63,9 @@ def check_app_status() -> dict[str, str]:
 
 
 # Mount sub-applications
-app.mount(server=weather_app, prefix="weather")
+app.mount(server=weather_app, namespace="weather")
 
-app.mount(server=news_app, prefix="news")
+app.mount(server=news_app, namespace="news")
 
 
 async def get_server_details():