Allow Single User

[rgaudin]

Fixed #95

This feature serves two purposes:

• sets a variable on both frontend and backend indicating that we are in single-user mode. this is the concept we'll use to switch between public SaaS and private single-user
• sets a single User ID that is sent to all users

This makes sure that anyone connecting is on the same session, sees the same projects. Even though the cookie might expire, re-requesting one gets the same User ID.

On the backend, if SINGLE_USER_ID is set, it is checked for existence on start or created if not. In the frontend, homepage checks whether it is expecting a single user mode (ENV) and if yes, fetches the User and Projects from backend before redirecting to /collections

[codecov]

Codecov Report

Attention: Patch coverage is 50.00000% with 14 lines in your changes missing coverage. Please review.

Project coverage is 73.24%. Comparing base (2f6e54f) to head (e254f34).
Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
backend/api/database/utils.py	30.76%	9 Missing ⚠️
backend/api/main.py	33.33%	2 Missing ⚠️
backend/api/routes/users.py	71.42%	1 Missing and 1 partial ⚠️
backend/api/constants.py	80.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #96      +/-   ##
==========================================
- Coverage   74.11%   73.24%   -0.88%     
==========================================
  Files          18       18              
  Lines         962      983      +21     
  Branches      115      120       +5     
==========================================
+ Hits          713      720       +7     
- Misses        226      239      +13     
- Partials       23       24       +1     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.