build: package local admin service

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

.env.example

@@ -0,0 +1,7 @@
+# .env.example
+ADMIN_PASSWORD=change-me
+SECRET_KEY=replace-with-at-least-16-random-characters
+CREDENTIAL_ENCRYPTION_KEY=replace-with-a-valid-fernet-key
+SYNC_INTERVAL_MINUTES=5
+DATA_DIR=/data
+DATABASE_URL=sqlite:////data/app.db