Rework authentication for local Cloud/Collab development (#35450)

This PR reworks authentication for developing Zed against a local
version of Cloud and/or Collab.

You will still connect the same way—using the `zed-local` script—but
will need to be running an instance of Cloud locally.

Release Notes:

- N/A

script/zed-local

@@ -213,7 +213,7 @@ setTimeout(() => {
           platform === "win32"
             ? "http://127.0.0.1:8080/rpc"
             : "http://localhost:8080/rpc",
-        ZED_ADMIN_API_TOKEN: "secret",
+        ZED_ADMIN_API_TOKEN: "internal-api-key-secret",
         ZED_WINDOW_SIZE: size,
         ZED_CLIENT_CHECKSUM_SEED: "development-checksum-seed",
         RUST_LOG: process.env.RUST_LOG || "info",