chore: rename cameleer3 to cameleer

Rename Java packages from com.cameleer3 to com.cameleer, module
directories from cameleer3-* to cameleer-*, and all references
throughout workflows, Dockerfiles, docs, migrations, and pom.xml.

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

ui/README.md

@@ -1,4 +1,4 @@
-# Cameleer3 UI
+# Cameleer UI
 
 React SPA built with [@cameleer/design-system](https://gitea.siegeln.net/cameleer/design-system) v0.1.28, TanStack Query, and Zustand.