fix: remove tmp skill codegen embedded repo from Samples

Removes the nested tmpgeneralupdate-skill-codegen directory (an untracked
clone of github.com/GeneralLibrary/generalupdate-skill-codegen) that was
accidentally placed under src/Hub/Samples/. The dedicated skill repo
already exists at github.com/GeneralLibrary/generalupdate-skill-codegen.

Adds tmpgeneralupdate-skill-codegen/ to .gitignore to prevent recurrence.

Co-Authored-By: Claude <noreply@anthropic.com>

Author: JusterZhu

.gitignore

@@ -25,6 +25,9 @@ bld/
 [Tt]est[Rr]esult*/
 [Bb]uild[Ll]og.*
 
+# Ignore temporary skill codegen embedded repo
+tmpgeneralupdate-skill-codegen/
+
 #NUNIT
 *.VisualState.xml
 TestResult.xml