flatbuffer base

flatbuffers/auth/auth.fbs

@@ -0,0 +1,11 @@
+namespace hmmmm.auth;
+
+// Client → Server: SHA-512(access_token + str(unix_timestamp / 30))
+table AuthRequest {
+    hash: [ubyte];  // 64 bytes
+}
+
+// Server → Client: seat assigned, current emulation state echoed
+table AuthResponse {
+    seat_id: uint64;
+}