chore: add coolify-ready docker packaging and deployment env template

.env.example

@@ -0,0 +1,20 @@
+# Runtime
+NODE_ENV=production
+PORT=3000
+STATE_FILE_PATH=/data/state.json
+
+# Webhook secrets
+X_WEBHOOK_SECRET=replace-me
+POLAR_WEBHOOK_SECRET=replace-me
+
+# Credit policy
+BASE_CREDITS=1
+INCLUDED_CHARS=25000
+STEP_CHARS=10000
+STEP_CREDITS=1
+MAX_CHARS_PER_ARTICLE=120000
+
+# Rate limits (requests per minute)
+WEBHOOK_RPM=120
+AUTH_RPM=30
+ACTION_RPM=60