[Feature] Implement Autologin on app startup

[GnejuszPompejusz]

Is your feature request related to a problem? Please describe

Typing my username and password every time I open the Android app is frustrating, especially since I use it daily on my device. It’s a repetitive step that slows down access.

Describe the solution you'd like

Add an autologin feature that triggers when the app starts. On launch, it should:

1. Check SecureStoragePlugin for saved accounts.
2. If an account has autoLogin: true, attempt login using stored credentials (e.g., authenticate(login, atob(password))).
3. On success, redirect to the main screen (router.push("/")).
4. On failure or no autologin account, fall back to the manual login screen.
   Store credentials securely using Android’s secure storage (via SecureStoragePlugin), and include a toggle in account settings to enable/disable autoLogin per account.

Describe alternatives you've considered

• Pre-filled fields: Could auto-fill login/password, but still requires a manual "Login" tap, which isn’t as seamless as autologin.
• Stay logged in: Thought about a persistent session (e.g., keeping a token), but this risks authorization issues (e.g., token expiration or server-side logout), forcing re-login anyway. Autologin avoids this by re-authenticating on startup, ensuring a fresh session without constant user input.

Additional context

This would streamline daily use for Android users while keeping security intact. Consider tying it to Android’s biometric auth (e.g., fingerprint) for extra protection if autologin is enabled. The autoLoginAttempted flag in sessionStorage could prevent repeated attempts in one session, resetting only on app close.

[SimonB50]

I was thinking about implementing something like this, but more as a "main" account system. It would also be a part of the notifications system (if I will be able to implement it) and maybe something more.

[GnejuszPompejusz]

We could add a class USER as follows:

// Pseudocode
class USER {
    String? Avatar;
    String id;
    String account;
    String password; // Consider replacing this with a getter for added security
    Bool autologin;
}

To improve the implementation, we can later introduce a condition check before widgets appear (e.g., splash screen). This could allow other services to initialize in the background during the splash screen display. Currently, the dashboard appears first, and if there is no authorization, the authentication screen is displayed.

Additionally, I suggest that when selecting a saved account, the login process should occur automatically after selecting the account, rather than requiring manual input of credentials.

From a security perspective, it may be worth replacing the password variable with a getter to ensure the password does not appear as a direct variable, reducing potential risks.

[SimonB50]

So, few things about this:

1. Implementing better security would be really hard since we have already limited resources to do so - the only option is to use biometric security (which stores credentials in a secure place) but it's not supported across all devices and I want this app to be used on ANY device. And if we were to implement 2 systems it would take a lot of time.
2. Account selector system needs additional click on the login button to make it possible to easily edit the password.
3. I don't think we can support avatars and if we even want to do that.

Despite of all of these things, auth system is already pretty secure since everything is happening on the device - we only track some basic analytics about userbase which comes with the default firebase implementation (just bundling the app with the firebase).

Also, while I will be implementing some things to make the app better, after messages PR merge and doing some QoL improvements to the app I will be limiting the development of the app since from what I saw, the userbase is pretty small - I'm still going to maintain the app and fix any of the bug, maybe even adding small changes but until I see any improvements, that it.