chore: add lockfile linting check and convert SSH URLs to HTTPS

- Add npm script to check for SSH URLs in package-lock.json
- Convert electron/node-gyp dependency from SSH to HTTPS URL
- Add workflow step to lint lockfile in CI environment

🤖 Generated with Claude Code

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

.github/workflows/pr-check.yml

@@ -24,6 +24,9 @@ jobs:
           cache: "npm"
           cache-dependency-path: package-lock.json
 
+      - name: Check for SSH URLs in lockfile
+        run: npm run lint:lockfile
+
       - name: Configure Git for HTTPS
         # Convert SSH URLs to HTTPS for git dependencies (e.g., @electron/node-gyp)
         # This is needed because SSH authentication isn't available in CI