feat: redesign match play and add broadcast tooling

scripts/migrations/0003-match-runtime.sql

@@ -0,0 +1,20 @@
+-- Optimistic locking for the match actor, the hosting IRC account for
+-- rejoining after a restart, and an undo log for rating changes.
+ALTER TABLE match ADD COLUMN IF NOT EXISTS revision integer NOT NULL DEFAULT 0;
+ALTER TABLE match ADD COLUMN IF NOT EXISTS irc_account text;
+
+CREATE TABLE IF NOT EXISTS rating_change (
+	id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
+	match_id uuid NOT NULL REFERENCES match(id) ON DELETE CASCADE,
+	subject text NOT NULL,
+	subject_id text NOT NULL,
+	before integer NOT NULL,
+	after integer NOT NULL,
+	won boolean NOT NULL,
+	created_at timestamptz NOT NULL DEFAULT now()
+);
+CREATE INDEX IF NOT EXISTS idx_rating_change_match ON rating_change (match_id);
+CREATE INDEX IF NOT EXISTS idx_rating_change_subject ON rating_change (subject_id);
+
+-- Matches the previous process left mid-flight are resumed by the runtime.
+CREATE INDEX IF NOT EXISTS idx_match_game_match_state ON match_game (match_id, state);