docs: fix GITEA_REPO format documentation

Update documentation to reflect that GITEA_REPO expects owner/repo
format (e.g., my-org/my-repo) instead of separate GITEA_ORG and
GITEA_REPO variables.

This matches the actual MCP server implementation in config.py.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

docs/DEBUGGING-CHECKLIST.md

@@ -128,7 +128,7 @@ cat ~/.config/claude/netbox.env
 
 # Project-level config (in target project)
 cat /path/to/project/.env
-# Should contain: GITEA_ORG, GITEA_REPO
+# Should contain: GITEA_REPO=owner/repo (e.g., my-org/my-repo)
 ```
 
 ---