Adds small italic notice in 3 sections when ComfyUI-USCG-CivitAI is
not installed:
1. Model 'Lookup Metadata from CivitAI' button section
2. LoRA 'Auto Append Trigger Words' section
3. LoRA 'Lookup Metadata from CivitAI' button section
Notice: 'Plugin feature — install [ComfyUI-USCG-CivitAI](github) for
auto-trigger detection + metadata lookup.'
DOM methods only - no innerHTML. Async-checks via /uscg-civitai/health.