fix: add ESLint config and correct artifacthub checksum

- .eslintrc.js: extends @headlamp-k8s/eslint-config (ESLint was failing with
  "couldn't find a configuration file")
- artifacthub-pkg.yml: replace placeholder checksum with actual sha256 of
  dist/main.js computed from production build
- pnpm-lock.yaml: restored to index (was incorrectly removed in amend attempt)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.eslintrc.js

@@ -0,0 +1,3 @@
+module.exports = {
+  extends: ['@headlamp-k8s/eslint-config'],
+};

artifacthub-pkg.yml

@@ -27,7 +27,7 @@ provider:
   name: privilegedescalation
 annotations:
   headlamp/plugin/archive-url: "https://github.com/privilegedescalation/headlamp-argocd-plugin/releases/download/v0.1.0/headlamp-argocd-0.1.0.tar.gz"
-  headlamp/plugin/archive-checksum: "sha256:REPLACE_WITH_ACTUAL_CHECKSUM"
+  headlamp/plugin/archive-checksum: "sha256:1f4df43f79b795bdf4f70e1e3aa5bacadf689ea5584fdadf92fb677faab21c2c"
   headlamp/plugin/version-compat: ">=0.26"
   headlamp/plugin/distro-compat: "in-cluster"
 changes: