Release v1.2.0

[MatiasOS]

Summary

• Update @openscan/explorer dependency from 1.2.0-alpha to 1.2.3-alpha
• Open browser directly on the network page (localhost:3030/#/31337) instead of the root URL
• Bump plugin version to 1.2.0

Changes

• package.json: Version bump to 1.2.0, explorer dependency updated to 1.2.3-alpha
• server.ts: getWebappUrl() now returns URL with network path (/#/31337) so users land directly on the relevant network page
• pnpm-lock.yaml: Lockfile updated accordingly

Test plan

• Run plugin locally and verify the browser opens to http://localhost:3030/#/31337
• Confirm explorer webapp loads correctly at the network-specific URL