storage: add initial postgres event persistence and schema migration

test/parrhesia/storage/adapters/postgres/events_test.exs

@@ -0,0 +1,52 @@
+defmodule Parrhesia.Storage.Adapters.Postgres.EventsTest do
+  use ExUnit.Case, async: true
+
+  alias Parrhesia.Protocol.EventValidator
+  alias Parrhesia.Storage.Adapters.Postgres.Events
+
+  test "normalize_event/1 decodes hex fields and extracts d_tag/expiration" do
+    pubkey = String.duplicate("a", 64)
+
+    event = %{
+      "pubkey" => pubkey,
+      "created_at" => 1_700_000_000,
+      "kind" => 30_023,
+      "tags" => [["d", "profile"], ["expiration", "1700001000"], ["p", String.duplicate("b", 64)]],
+      "content" => "hello",
+      "sig" => String.duplicate("c", 128)
+    }
+
+    id = EventValidator.compute_id(event)
+    event = Map.put(event, "id", id)
+
+    assert {:ok, normalized} = Events.normalize_event(event)
+    assert normalized.created_at == 1_700_000_000
+    assert normalized.kind == 30_023
+    assert normalized.d_tag == "profile"
+    assert normalized.expires_at == 1_700_001_000
+    assert normalized.id == Base.decode16!(id, case: :lower)
+    assert normalized.pubkey == Base.decode16!(pubkey, case: :lower)
+  end
+
+  test "candidate_wins_state?/2 uses created_at then lexical id tie-break" do
+    assert Events.candidate_wins_state?(
+             %{created_at: 11, id: <<2>>},
+             %{event_created_at: 10, event_id: <<255>>}
+           )
+
+    refute Events.candidate_wins_state?(
+             %{created_at: 9, id: <<0>>},
+             %{event_created_at: 10, event_id: <<255>>}
+           )
+
+    assert Events.candidate_wins_state?(
+             %{created_at: 10, id: <<1>>},
+             %{event_created_at: 10, event_id: <<2>>}
+           )
+
+    refute Events.candidate_wins_state?(
+             %{created_at: 10, id: <<3>>},
+             %{event_created_at: 10, event_id: <<2>>}
+           )
+  end
+end