chore: set meta.mainProgram for a few packages

pkgs/applications/misc/visidata/default.nix

@@ -165,6 +165,7 @@ buildPythonApplication rec {
 
   meta = {
     description = "Interactive terminal multitool for tabular data";
+    mainProgram = "visidata";
     license = lib.licenses.gpl3;
     maintainers = with lib.maintainers; [
       raskin

pkgs/by-name/le/lesspipe/package.nix

@@ -237,6 +237,7 @@ stdenv.mkDerivation rec {
       plist and archive formats, perl storable data and gpg encrypted files.
       This does require additional helper programs being installed.
     '';
+    mainProgram = "lesspipe.sh";
     homepage = "https://github.com/wofr06/lesspipe";
     platforms = platforms.all;
     license = licenses.gpl2Only;

pkgs/by-name/lo/local-ai/package.nix

@@ -638,6 +638,7 @@ let
 
     meta = with lib; {
       description = "OpenAI alternative to run local LLMs, image and audio generation";
+      mainProgram = "local-ai";
       homepage = "https://localai.io";
       license = licenses.mit;
       maintainers = with maintainers; [