Rename package to scoped @valknar/triggershell

Matches vpinball-wasm's move back to a scoped name: an unscoped
package on this Gitea npm registry can't be mapped via a normal
`.npmrc` `@scope:registry=` entry, since the registry doesn't proxy
npmjs.org. Scoping lets any consumer add one registry line instead of
pinning a tarball URL per dependency.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012hQoM3jJT1Lx7CMTciMzvD

package.json

@@ -1,6 +1,6 @@
 {
-  "name": "triggershell",
-  "version": "1.1.0",
+  "name": "@valknar/triggershell",
+  "version": "1.2.0",
   "license": "MIT",
   "type": "module",
   "repository": {