fix: update deprecated huggingface-cli to hf CLI

huggingface-cli was renamed to hf in 2025. Use `hf models info`
instead of `huggingface-cli search`.

Identified by coderabbit (PR #5 round 3 review).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: belumume

deep-brainstorming/references/research-prompts.md

@@ -178,7 +178,7 @@ Use when an agent reports "X doesn't exist" or "X is not available." NEVER accep
 ```bash
 # Model existence (HuggingFace models, not PyPI packages)
 # HuggingFace API: curl -s https://huggingface.co/api/models/<org>/<model> | head
-# or: huggingface-cli search <model-name>
+# or: hf models info <model-name>
 
 # Package existence
 pip index versions <package-name>