feat(plans): enhance plan management with dynamic providers, improved UI, and bug fixes

Dynamic Provider Integration:
  - Replace hardcoded provider arrays with database-driven payment_providers lookup
  - Display provider status (Active/Inactive) in selection dropdowns
  - Add provider_variant_id and provider_product_id input fields to plan configuration
  - Update EditPlan and SubscriptionForm with dynamic provider selection
  - Add empty state handling with helpful guidance when no providers exist

  UI/UX Improvements:
  - Format billing_cycle_days to readable text (Daily, Weekly, Monthly, Quarterly, Annually)
  - Add color-coded badges for billing cycle frequency
  - Fix plan_providers and plan_feature_limits count display with eager loading
  - Implement intelligent color coding for count indicators
  - Add visual status indicators for provider availability

  Database Compatibility:
  - Fix SQLite strftime() compatibility across all dashboard widgets
  - Fix CAST AS REAL syntax in ChurnAnalysis widget
  - Add database-agnostic date and cast expression methods
  - Support MySQL, SQLite, PostgreSQL, and SQL Server

  Bug Fixes:
  - Fix null reference error in SubscriptionForm provider_data access
  - Add null safety checks for new subscription creation
  - Optimize queries with withCount() to prevent N+1 issues

  Performance Optimizations:
  - Add eager loading with withCount() for relationship counts
  - Optimize plan provider and feature limit queries
  - Prevent N+1 query issues in resource tables

  BREAKING CHANGE: Plan provider configuration now uses dynamic provider options
  from payment_providers table instead of hardcoded list.

app/Filament/Resources/PlanResource.php

@@ -146,10 +146,34 @@ class PlanResource extends Resource
                     ->money('USD')
                     ->sortable(),
 
-                Tables\Columns\TextColumn::make('billing_cycle_display')
+                Tables\Columns\TextColumn::make('billing_cycle_days')
                     ->label('Billing Cycle')
                     ->badge()
-                    ->color('primary'),
+                    ->color(fn (int $state): string => match ($state) {
+                        1 => 'success',      // Daily - green
+                        7 => 'info',         // Weekly - blue
+                        14 => 'primary',     // Bi-weekly - primary blue
+                        30 => 'warning',     // Monthly - orange
+                        60 => 'gray',        // Bi-monthly - gray
+                        90 => 'purple',      // Quarterly - purple
+                        180 => 'danger',     // Semi-annually - red
+                        365 => 'primary',    // Annually - primary blue
+                        730 => 'gray',       // Biennially - gray
+                        default => 'gray'    // Custom cycles - gray
+                    })
+                    ->formatStateUsing(fn (int $state): string => match ($state) {
+                        1 => 'Daily',
+                        7 => 'Weekly',
+                        14 => 'Bi-weekly',
+                        30 => 'Monthly',
+                        60 => 'Bi-monthly',
+                        90 => 'Quarterly',
+                        180 => 'Semi-annually',
+                        365 => 'Annually',
+                        730 => 'Biennially',
+                        default => "{$state} days"
+                    })
+                    ->sortable(),
 
                 Tables\Columns\IconColumn::make('is_active')
                     ->label('Active')
@@ -157,19 +181,29 @@ class PlanResource extends Resource
                     ->trueColor('success')
                     ->falseColor('danger'),
 
-                Tables\Columns\TextColumn::make('planProviders_count')
+                Tables\Columns\TextColumn::make('plan_providers_count')
                     ->label('Providers')
-                    ->counts('planProviders')
+                    ->getStateUsing(fn ($record) => $record->plan_providers_count ?? 0)
                     ->badge()
-                    ->color('info')
-                    ->sortable(false),
+                    ->color(fn ($record) => match (true) {
+                        $record->plan_providers_count === 0 => 'danger',
+                        $record->plan_providers_count === 1 => 'warning',
+                        $record->plan_providers_count >= 3 => 'success',
+                        default => 'info'
+                    })
+                    ->sortable(),
 
-                Tables\Columns\TextColumn::make('planFeatureLimits_count')
+                Tables\Columns\TextColumn::make('plan_feature_limits_count')
                     ->label('Features')
-                    ->counts('planFeatureLimits')
+                    ->getStateUsing(fn ($record) => $record->plan_feature_limits_count ?? 0)
                     ->badge()
-                    ->color('warning')
-                    ->sortable(false),
+                    ->color(fn ($record) => match (true) {
+                        $record->plan_feature_limits_count === 0 => 'danger',
+                        $record->plan_feature_limits_count >= 5 => 'success',
+                        $record->plan_feature_limits_count >= 3 => 'info',
+                        default => 'warning'
+                    })
+                    ->sortable(),
 
                 Tables\Columns\TextColumn::make('sort_order')
                     ->label('Order')
@@ -235,6 +269,15 @@ class PlanResource extends Resource
             ]);
     }
 
+    public static function getEloquentQuery(): Builder
+    {
+        return parent::getEloquentQuery()
+            ->withCount([
+                'planProviders',
+                'planFeatureLimits',
+            ]);
+    }
+
     public static function getRelations(): array
     {
         return [