chore: initialize project with package.json, .env.example and .gitignore

Set up the Node.js project skeleton, define environment variable
template, and exclude secrets, certs, and nginx runtime from version control.

.env.example

@@ -0,0 +1,11 @@
+# Copy this file to .env and replace the placeholder values.
+
+# Gitea token used to list repos and branches.
+GITEA_TOKEN=replace-with-your-gitea-token
+
+# IPADS API key used by the default quota command.
+IPADS_API_KEY=replace-with-your-ipads-api-key
+
+# Optional overrides.
+# KANBAN_GITEA_BASE_URL=http://gahow-pc.ipads-lab.se.sjtu.edu.cn:3300
+# KANBAN_AUTH_TOKEN=replace-with-a-long-random-login-token