fix(docker): keep server/reset-admin.js in the build context (#1339)

The Dockerfile copies server/reset-admin.js (the admin recovery
script), but .dockerignore also listed it, so it was stripped from
the build context and the image build failed with a not-found error.
Drop the ignore entry so the COPY resolves again.

.dockerignore

@@ -30,7 +30,6 @@ Thumbs.db
 sonar-project.properties
 server/tests/
 server/vitest.config.ts
-server/reset-admin.js
 **/*.test.ts
 **/*.spec.ts
 wiki/