feat(games): add the generic d6 oracle game package

Serves as the reference implementation of the game package contract:
rules, spark tables, character backgrounds, and an example command.

games/generic/scripts/README.md

@@ -0,0 +1,12 @@
+# Tool scripts
+
+Game-specific tooling lives here. There are two ways to ship it:
+
+1. **CLI commands** — export a `commands` map from the game's `index.js`. The
+   `journal` CLI exposes each entry as `journal <name>`, with the shared dice
+   and table helpers passed in. This is the recommended path for anything the
+   agent calls during play (see `../index.js` for the `background` example).
+2. **Standalone scripts** — drop one-off executables in this directory, for
+   jobs like importing content or converting data, and run them with `node`.
+
+See `docs/games.md` for the full contract.