docs: fix the claude mcp add form, pin the package index, document known limitations

The --env option swallowed the server name, so the stdio command is reordered. uvx now always
names the project registry because the package name is not registered on public PyPI.
README gains a Known limitations section, the READ_ONLY wording is corrected, packaging.md
warns about --extra-index-url and the Le Chat admin requirement is mentioned.

docs/deployment.md

@@ -67,7 +67,7 @@ Check it: `curl http://127.0.0.1:8080/health`.
 
 Terminate TLS at a reverse proxy. `PUBLIC_BASE_URL` must be the public https URL (it is required
 for OAuth, and http is only accepted for loopback hosts). Mistral Le Chat needs a valid public
-certificate.
+certificate, and adding a connector there may require workspace admin rights.
 
 Caddy: