Add comprehensive translations for main interface

Translation Updates:
- Added all missing translations for main interface elements
- Added translations for periods, declarations, and status messages
- Added success and error message translations
- Added French translations for all new keys
- Improved user experience with proper bilingual support

Main Interface Translations Added:
- DeclarationTVAMainInterface, DeclarationTVAPeriods, DeclarationTVADeclarations
- PeriodName, StartDate, EndDate, Status, Actions
- CreateDeclaration, DeclarationNumber, NetVATDue
- Validate, Submit, View buttons
- Status indicators (Draft, Validated, Submitted)
- Success/Error messages for all operations

The main interface is now fully translated in both English and French!

langs/en_US/declarationtva.lang

@@ -372,3 +372,33 @@ ErrorCSRFToken = Security token error. Please try again.
 NoChangesDetected = No changes detected in the configuration.
 DeclarationTVAConfiguration = DeclarationTVA Configuration
 ConfigurePCGAccounts = Configure PCG Accounts
+
+# Main Interface Translations
+DeclarationTVAMainInterface = CA-3 VAT Declaration
+DeclarationTVAPeriods = Periods
+DeclarationTVADeclarations = Declarations
+NoPeriodsFound = No periods found
+NoDeclarationsFound = No declarations found
+PeriodName = Period Name
+StartDate = Start Date
+EndDate = End Date
+Status = Status
+Actions = Actions
+CreateDeclaration = Create Declaration
+DeclarationNumber = Declaration Number
+Period = Period
+NetVATDue = Net VAT Due
+Validate = Validate
+Submit = Submit
+View = View
+StatusDraft = Draft
+StatusValidated = Validated
+StatusSubmitted = Submitted
+
+# Success and Error Messages
+DeclarationCreated = Declaration created successfully
+DeclarationValidated = Declaration validated successfully
+DeclarationSubmitted = Declaration submitted successfully
+ErrorCreatingDeclaration = Error creating declaration
+ErrorValidatingDeclaration = Error validating declaration
+ErrorSubmittingDeclaration = Error submitting declaration

langs/fr_FR/declarationtva.lang

@@ -361,3 +361,33 @@ ErrorCSRFToken = Erreur de jeton de sécurité. Veuillez réessayer.
 NoChangesDetected = Aucun changement détecté dans la configuration.
 DeclarationTVAConfiguration = Configuration DeclarationTVA
 ConfigurePCGAccounts = Configurer les comptes PCG
+
+# Main Interface Translations
+DeclarationTVAMainInterface = Déclaration TVA CA-3
+DeclarationTVAPeriods = Périodes
+DeclarationTVADeclarations = Déclarations
+NoPeriodsFound = Aucune période trouvée
+NoDeclarationsFound = Aucune déclaration trouvée
+PeriodName = Nom de la période
+StartDate = Date de début
+EndDate = Date de fin
+Status = Statut
+Actions = Actions
+CreateDeclaration = Créer une déclaration
+DeclarationNumber = Numéro de déclaration
+Period = Période
+NetVATDue = TVA nette due
+Validate = Valider
+Submit = Soumettre
+View = Voir
+StatusDraft = Brouillon
+StatusValidated = Validée
+StatusSubmitted = Soumise
+
+# Success and Error Messages
+DeclarationCreated = Déclaration créée avec succès
+DeclarationValidated = Déclaration validée avec succès
+DeclarationSubmitted = Déclaration soumise avec succès
+ErrorCreatingDeclaration = Erreur lors de la création de la déclaration
+ErrorValidatingDeclaration = Erreur lors de la validation de la déclaration
+ErrorSubmittingDeclaration = Erreur lors de la soumission de la déclaration