chore: point homepage at the dedicated roninforge.org/claude-code-cost page

Was pointing at the BudgetClaw tutorial, which describes a different tool.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

Author: solomonic

.claude-plugin/plugin.json

@@ -8,7 +8,7 @@
     "name": "RoninForge",
     "url": "https://roninforge.org"
   },
-  "homepage": "https://roninforge.org/tutorials/how-to-see-ongoing-project-costs",
+  "homepage": "https://roninforge.org/claude-code-cost",
   "repository": "https://github.com/RoninForge/claude-code-cost",
   "license": "MIT",
   "keywords": [