fix: resolve PR conflicts with origin/main

- Remove .github/FUNDING.yml (upstream FreeCAD only, not Kindred)
- Sync .gitignore, .pre-commit-config.yaml, .pylintrc from origin/main
- Sync README.md, cMake/FindNETGEN.cmake from origin/main
- Sync pixi.lock, pixi.toml from origin/main
- Reset mods/ztools submodule pointer to match origin/main

.gitignore

@@ -10,6 +10,7 @@
 !/.pre-commit-config.yaml
 !/.pylintrc
 !/.github/
+!/.gitea/
 !/contrib/.vscode/
 !*.gitattributes
 !*.gitignore
@@ -70,3 +71,6 @@ files_to_translate.txt
 # pixi environments
 .pixi
 *.egg-info
+
+# mdBook build output
+docs/book/