chore: drop container labels from cadvisor, require webtop CUSTOM_USER, trim env template comments

goclaw/.env.example

@@ -2,13 +2,11 @@
 #
 #   cp .env.example .env
 
-# Bearer token for the gateway API and dashboard. MUST NOT be blank -- a blank
-# token serves the agent gateway, and the tools its agents can run, to anyone.
+# Bearer token for the gateway API and dashboard. Required.
 # Generate one with: openssl rand -hex 16
 GOCLAW_GATEWAY_TOKEN=
 
 # AES-256-GCM key encrypting the LLM provider keys stored in PostgreSQL.
-# Changing it makes every stored key unreadable.
 # Generate one with: openssl rand -hex 32
 GOCLAW_ENCRYPTION_KEY=