Remove obsolete scripts and files, update site builder configurations

- Deleted the `import_plans.py`, `run_tests.py`, and `test_run.py` scripts as they are no longer needed.
- Updated the initial migration dependency in `0001_initial.py` to reflect recent changes in the `igny8_core_auth` app.
- Enhanced the implementation plan documentation to include new phases and updates on the site builder project.
- Updated the `vite.config.ts` and `package.json` to integrate testing configurations and dependencies for the site builder.

site-builder/tsconfig.app.json

@@ -5,7 +5,7 @@
     "useDefineForClassFields": true,
     "lib": ["ES2022", "DOM", "DOM.Iterable"],
     "module": "ESNext",
-    "types": ["vite/client"],
+    "types": ["vite/client", "vitest/globals"],
     "skipLibCheck": true,
 
     /* Bundler mode */