refactor(feature:client): merge ViewModels, add charge validation, fix empty chargeOptions crash

[biplab1]

Fixes - Jira-#458

Summary of Changes:

• Fix crash by adding default selected charge values to ChargeDialogUiState.AllChargesV2 when chargeOptions is empty.
• Merge two dialog view model into client charge view model
• Show snackbar message on successful charge creation
• Add input validation dialog input fields and enable/disable button accordingly
• Make 'ChargeOptions` fields nullable to handle missing field in API response

Before Fix (without charges setup in web-app):

before-fix-client-charges-dialog.mp4

Before Fix (with charges setup in web-app and no database bypass):

before-fix-client-charges-dialog-no-charge-setup-no-database-bypass.webm

After Fix:
Note:

• The newly created charge appears second from the top in the screen recording
• The charges list is fetched directly from API, bypassing the database
  (the database handling is a work in progress in another PR)

Client-Charges-Dialog-Merge-Viewmodels.mp4

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• Run the static analysis check ./gradlew check or ci-prepush.sh to make sure you didn't break anything

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[biplab1]

Note: Merge this after #2428

[Nagarjuna0033]

@biplab1 I think for now we can focus only on the issues that are crashing the application or any api error handling things, because Show snackbar message on successful charge creation, Refactor dialog screen content for better readability and reuse,
Add resetUiState to handle dialog state after successful submission are not that much important as the feature is working. As you know we will be getting new mockups you can take a look into those. we may need to refactor lot of things and may be need to remove current ui components and if necessary, screens also. Then this work will be waste of time. So, it would be better we can fastly wrap up cleaning kmp-impl branch and merging into dev branch. correct me if I am wrong.

@niyajali @revanthkumarJ @itsPronay your thoughts on this

[revanthkumarJ]

@biplab1 I think for now we can focus only on the issues that are crashing the application or any api error handling things, because Show snackbar message on successful charge creation, Refactor dialog screen content for better readability and reuse, Add resetUiState to handle dialog state after successful submission are not that much important as the feature is working. As you know we will be getting new mockups you can take a look into those. we may need to refactor lot of things and may be need to remove current ui components and if necessary, screens also. Then this work will be waste of time. So, it would be better we can fastly wrap up cleaning kmp-impl branch and merging into dev branch. correct me if I am wrong.

@niyajali @revanthkumarJ @itsPronay your thoughts on this

I also think same like when i see mifos-mobile or template we have used Actions , Events , BaseViewModel and some neat architecture
if we are going to implement similarly here in android client while implementing mockups then,
how we handled snackbars , states everything should be moved to viewmodel and change current implementation completely, so may be we can fix small small ui fixes there

[biplab1]

@Nagarjuna0033 @revanthkumarJ Just to clarify — the feature wasn’t fully working before.

It was crashing when chargeOptions came back empty. I added the necessary chargeOptions data so the API response works as expected, and updated the dialog to handle nullable entries to prevent it getting stuck on load.

So the snackbar, state reset, and dialog refactor are not just polish — they fix real flow blockers and ensure the screen stays stable as we transition to the new UI.

Skipping these now risks the same crash or broken flow later.

[niyajali]

@Nagarjuna0033 @revanthkumarJ @itsPronay @Aditya3815 @HekmatullahAmin Guys review this

[biplab1]

@niyajali I’ve merged the two view models as discussed. Please let me know if anything else needs to be done. If everything looks good, kindly go ahead and merge it.