feat: Add authentication flow and bottom tab navigation

[najuna-brian]

Description

Implements authentication flow and navigation structure for Formulus mobile app.

Changes

• Added (screens) Welcome, Server Configuration, and Login screens with QR scanning
• Added Bottom tab navigation (Home, Forms, Observations, Sync, More) and menu drawer

Testing

• ✅ Authentication flow works end-to-end
• ✅ Server configuration persists
• ✅ QR scanning works
• ✅ Navigation between tabs works
• ✅ Menu drawer opens/closes properly

the colours and other customizations will be adopted when the tokens have been merged

Closes #47

[Bahati308]

Hello @najuna-brian, thanks for the great input. In my opinion, we could keep the sign-in page content configurable through the settings, and introduce a separate user authentication flow where users can create an account and log in using their own credentials.

[r0ssing]

Thanks! This looks great😎! I believe we have a version of the logo with transparent background somewhere (but I'm out of office these days, so I will check that when I'm back, in case that looks smoother?)

As for use creation, my initial thought is to do that through the web portal or the CLI?

[Mishael-2584]

Looks great. I love the updated look and menu. I think I also agree with emil that we could still have user creation via synkronus portal or CLI and then the login to be via the settings.

[najuna-brian]

@r0ssing, @Mishael-2584
Here's the complete app flow demo from installation to logout for the changes i have applied as guided above.
This shows the new welcome screen, QR-based setup for an admin user created from synkronus-cli
▶️ Watch App Flow Demo

[najuna-brian]

As for use creation, my initial thought is to do that through the web portal or the CLI?

Thanks, In the changes i have made, i have considered this, and also making sure features are available based on user role registered from the cli/synkronus portal

[najuna-brian]

Hi @Ndacyayisenga-droid
for the Auto Label PR Check Failing should we enable PR automation? The auto-labeler needs write permissions based on the erorr

Would it need change to the workflow permissions to Enable "Allow GitHub Actions to create and approve pull requests"

This enables automated PR labeling while keeping other permissions restricted. The failure isn't blocking the merge, but the fix would enable this workflow going forward.

[r0ssing]

Wow! This looks great!! 👌 I also really like that you added a button for observations - we can definitely so something interesting work that screen (general statistics or something)