shell: add datasette wrapper with metadata.json

default.nix

@@ -47,5 +47,33 @@ lib.makeScope pkgs.newScope (
       }
     );
     sidx = self.sidx-crate2nix.rootCrate.build;
+    datasette-wrapped = self.callPackage (
+      {
+        datasette,
+        datasette-metadata,
+        makeWrapper,
+        runCommand,
+      }:
+      runCommand "datasettew" { nativeBuildInputs = [ makeWrapper ]; } ''
+        mkdir -p "$out/bin"
+        makeWrapper ${lib.getExe datasette} "$out/bin/datasettew" \
+          --add-flags --metadata=${datasette-metadata}
+      ''
+    ) { };
+    datasette-metadata = self.callPackage (
+      { formats }:
+      (formats.json { }).generate "datasette-metadata.json" {
+        "databases" = {
+          "sidx" = {
+            "tables" = {
+              "Hash" = {
+                "label_column" = "hash";
+              };
+            };
+          };
+        };
+
+      }
+    ) { };
   }
 )