publish as catena-corpus on PyPI and npm

Both registries already have a `catena`: an HPE blockchain client on PyPI,
and a JavaScript OOP wrapper at 2.2.0 on npm. Neither is going anywhere, so
the distributions take a name that is free on both.

The Python import is unaffected — a distribution name and a module name are
independent there, so `pip install catena-corpus` still gives `import
catena`, and nothing in the examples or the bindings changes. On npm the
package name is the import specifier, so that one does change: `import
{ chunkMarkdown } from "catena-corpus"`.

The crates keep their own names. `catena` is free on crates.io.

examples/typescript/package.json

@@ -7,7 +7,7 @@
     "search": "node --experimental-strip-types src/search-and-rerank.ts"
   },
   "dependencies": {
-    "catena": "file:../../crates/bindings/npm/dist"
+    "catena-corpus": "file:../../crates/bindings/npm/dist"
   },
   "devDependencies": {
     "@types/node": "^22"