Upgrade path to Pydantic 2.0

Major path updates include:

- frontend:
  - Node 16 to 18
  - Latest Pinia requires changes in `stores`, where imports are not required, and parameter declaration must happen in functions.
- backend and celeryworker:
  - Python 3.9 to 3.11
  - Poetry to Hatch
  - Postgres 14 to 15

Author: ai-28

{{cookiecutter.project_slug}}/backend/app/.python-version

@@ -1 +1 @@
-3.9.4
+3.11.0

{{cookiecutter.project_slug}}/backend/app/__version__.py

@@ -0,0 +1 @@
+__version__="0.1.0"