fix(infra): convert apps/tools to submodule, fix Dockerfile paths

Move tools code to its own repo (asepharyana/asepharyana-hub-tools)
and add as git submodule following the existing app pattern.
Fix Dockerfile paths to use apps/tools/ prefix since build context
is the repo root.

Co-Authored-By: Kilo <kilo@kilo.ai>

.gitmodules

@@ -4,3 +4,6 @@
 [submodule "apps/hub"]
 	path = apps/hub
 	url = https://github.com/asepharyana/asepharyana-hub-hub.git
+[submodule "apps/tools"]
+	path = apps/tools
+	url = https://github.com/asepharyana/asepharyana-hub-tools.git