feat: prefix Aether plugin slug

Rename the canonical plugin slug to tribe-one-aether and update contract docs/tests accordingly.

README.md

@@ -53,7 +53,7 @@ The package pin is kept at `@internet-privacy/marmot-ts@0.5.1`.
 ```json
 {
   "id": "org.tribe-one.plugins.aether",
-  "slug": "aether",
+  "slug": "tribe-one-aether",
   "display_name": "Aether",
   "version": "0.2.0",
   "entry_module": "TribeOne.TribesPlugin.Aether.Plugin",

manifest.json

@@ -1,6 +1,6 @@
 {
   "id": "org.tribe-one.plugins.aether",
-  "slug": "aether",
+  "slug": "tribe-one-aether",
   "display_name": "Aether",
   "version": "0.2.0",
   "description": "Local social feed and chat for Tribes, including NIP-17 direct messages.",

test/aether/manifest_test.exs

@@ -36,7 +36,7 @@ defmodule TribeOne.TribesPlugin.Aether.ManifestTest do
 
     test "identity fields are namespaced", %{manifest: manifest} do
       assert manifest["id"] == "org.tribe-one.plugins.aether"
-      assert manifest["slug"] == "aether"
+      assert manifest["slug"] == "tribe-one-aether"
       assert manifest["otp_app"] == "tribe_one_aether"
     end