docs: replace static screenshot with animated demo GIF

Author: backstabslash

README.md

@@ -8,7 +8,7 @@ A fast, zero-dependency CLI cost calculator and [statusline provider](#claude-co
 
 Parses JSONL logs from `~/.claude/projects/`, deduplicates streaming responses, and breaks down spending by model, day, project, and month — with accurate per-model pricing including cache write tiers, long-context premiums, and web search costs.
 
-![goccc output](https://github.com/user-attachments/assets/e711b832-b5c2-44c3-a627-428dba350cf6)
+![demo](https://github.com/user-attachments/assets/a65fc389-951d-47bc-9a69-5f498f3c1d32)
 
 ## Table of Contents