feat(i18n): fix widgets, pipeline & mechanic boards + missing translations

Follow-up to previous i18n pass — user reported many visible RO strings on
EN/RU locales because auto-wrap missed:
  - Stat::make() first-arg labels in StatsOverview, FinanceOverview, PlatformStats
  - $heading static in LowStockTable (converted to getHeading() method)
  - Pipeline board Blade view: 40+ literal strings wrapped with {{ __() }}
  - Mechanic board Blade view: statuses, buttons, block modal
  - PipelineBoard.php hardcoded tag labels, stage labels, notify strings
  - MechanicBoard.php confirmBlock notification

Added human RU + EN translations for the visible strings shown in the
screenshots (dashboard widgets, Client/Vehicle list breadcrumbs & columns,
pipeline board topbar/stats/filters/cards/detail panel/quick actions,
mechanic board stats/statuses/block modal). All 306 tests pass.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

app/Filament/Tenant/Widgets/StatsOverview.php

@@ -21,27 +21,27 @@ class StatsOverview extends BaseWidget
         $todayAppointments = Appointment::whereDate('date', today())->count();
 
         return [
-            Stat::make('Clienți', Client::count())
+            Stat::make(__('Clienți'), Client::count())
                 ->description(__('Total în baza de date'))
                 ->icon('heroicon-o-users')
                 ->color('primary'),
 
-            Stat::make('Mașini', Vehicle::count())
+            Stat::make(__('Mașini'), Vehicle::count())
                 ->description(__('Total înregistrate'))
                 ->icon('heroicon-o-truck')
                 ->color('info'),
 
-            Stat::make('Cereri noi', $newLeads)
+            Stat::make(__('Cereri noi'), $newLeads)
                 ->description(__('De procesat'))
                 ->icon('heroicon-o-inbox-arrow-down')
                 ->color($newLeads > 0 ? 'warning' : 'success'),
 
-            Stat::make('Deal-uri active', $openDeals)
+            Stat::make(__('Deal-uri active'), $openDeals)
                 ->description(__('În pipeline'))
                 ->icon('heroicon-o-funnel')
                 ->color('primary'),
 
-            Stat::make('Programări azi', $todayAppointments)
+            Stat::make(__('Programări azi'), $todayAppointments)
                 ->description(today()->format('d.m.Y'))
                 ->icon('heroicon-o-calendar')
                 ->color('success'),