Claim Tiny Titan badge: add achievement:tiny-titan Space tag

The write-up and README already claim Tiny Titan (Qwen2.5-VL-3B, under the
4B line), but the Space metadata only declared offgrid/llama/fieldnotes.
Add the achievement:tiny-titan tag so the badge is registered on the
official hackathon Space.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

README.md

@@ -14,6 +14,7 @@ tags:
 - achievement:offgrid
 - achievement:llama
 - achievement:fieldnotes
+- achievement:tiny-titan
 thumbnail: >-
   https://cdn-uploads.huggingface.co/production/uploads/67a39e9465c06c95d452bd6d/Z_pvYNAWsx5oR24zkUFZg.png
 ---