i18n: fix widget heading, translate Select options from model consts, +40 keys

- LowStockTable: rename getHeading → getTableHeading (correct Filament API)
- Global I18n::opts() helper wraps Model::CONST values in __() so
  Select dropdowns show translated status/type/season/etc. labels
- Sed-transform ->options(X::CONST), ->options(array_combine(X::A,X::A)),
  and formatStateUsing(fn($s)=>X::CONST[$s]??$s) → wrap with __()
  (58 options + 10 combines + 7 formatStateUsing across 28 files)
- CalendarBoard: all 7 day names now via __() (was missing 4)
- calendar-board.blade: fix untranslated 'săptămâna curentă', 'capacitate',
  'rata confirmare', 'mediu', 'plin', 'Pod / Zi' / 'Mecanic / Zi'
- +40 RU/EN translations (Client & Auto, Maistru / Mecanic, Programat,
  Sosit, Finalizat, Anulat, Neprezentat, days of week, calendar KPIs)

All 306 tests pass.

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

app/Filament/Central/Resources/SuperAdminResource.php

@@ -58,7 +58,7 @@ class SuperAdminResource extends Resource
                 ->columns(1)
                 ->schema([
                     Forms\Components\Select::make('role')
-                        ->options(SuperAdmin::ROLES)
+                        ->options(\App\Support\I18n::opts(SuperAdmin::ROLES))
                         ->default('support')
                         ->required()
                         ->helperText(__('Owner = drepturi totale. Admin = aproape la fel. Sales = doar tenanți + planuri. Finance = facturi. Support = read-only.')),
@@ -115,7 +115,7 @@ class SuperAdminResource extends Resource
                 Tables\Columns\TextColumn::make('created_at')->date(),
             ])
             ->filters([
-                Tables\Filters\SelectFilter::make('role')->options(SuperAdmin::ROLES),
+                Tables\Filters\SelectFilter::make('role')->options(\App\Support\I18n::opts(SuperAdmin::ROLES)),
                 Tables\Filters\TernaryFilter::make('is_active')->label(__('Activ')),
             ])
             ->actions([