docs: stop naming the middleware

An agent talks to URLs that honour a contract: an MCP endpoint, an OIDC token
endpoint, an OpenAI-shaped LLM endpoint. Whatever serves those URLs is
replaceable, and naming it in an agent's code or docs implies a coupling that
does not exist.

Every product name is gone from prose, comments and identifiers, replaced by
what the agent actually depends on. Where a behaviour of the current middleware
leaks into the contract — the second audience scope, the tool ACL — the text
now says what the caller must do and why, not who imposes it.

One string survives and cannot be fixed here: the broker client an agent must
name in its audience scopes is itself named after the middleware. Closing that
means renaming it in Keycloak and following the rename through the gateway
configuration and LibreChat. Recorded as a blocker.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

pyproject.toml

@@ -13,7 +13,7 @@ dependencies = [
     # implementation is the safer base for the others to interoperate with.
     "a2a-sdk[http-server]>=1.1.2,<2",
     # Reasoning and tool calling. -slim keeps the dependency surface to the
-    # providers actually used; [openai] because the Kong AI gateway speaks the
+    # providers actually used; [openai] because the LLM endpoint speaks the
     # OpenAI protocol, [mcp] for the MCP client.
     "pydantic-ai-slim[openai,mcp]>=2.35.3,<3",
     "httpx2>=2.12.0,<3",