Fix remaining repo.anhonesthost.net references in user-facing code

- help_commands.rs: fetch HOW-TO-USE.md from GitHub raw instead of Gitea
- DockerSettings.tsx: display GHCR image address in settings UI
- HOW-TO-USE.md: update registry description to ghcr.io

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/src-tauri/src/commands/help_commands.rs

@@ -2,7 +2,7 @@ use std::sync::OnceLock;
 use tokio::sync::Mutex;
 
 const HELP_URL: &str =
-    "https://repo.anhonesthost.net/cybercovellc/triple-c/raw/branch/main/HOW-TO-USE.md";
+    "https://raw.githubusercontent.com/shadowdao/triple-c/main/HOW-TO-USE.md";
 
 const EMBEDDED_HELP: &str = include_str!("../../../../HOW-TO-USE.md");