Stage 13 — Notifications: Telegram bot + multi-channel + service reminders

Schema:
- clients.telegram_chat_id (linked via /start contact-share)
- clients.notify_prefs (per-client channel order override)
- service_reminders_sent (dedup ledger for the daily cron)

Telegram (per tenant):
- TelegramService (sendMessage, getMe, setWebhook with auto-generated secret)
- Bot token stored in companies.settings.telegram.bot_token
- Webhook /telegram/webhook/{slug} validates X-Telegram-Bot-Api-Secret-Token,
  matches client by last 9 digits of phone, persists chat_id, replies confirm
- /start prompts share-contact; /stop unlinks chat_id

NotificationDispatcher refactor:
- Multi-channel: telegram first if chat_id + bot configured, then email
- Backwards-compat with legacy boolean notify.{type} flags
- 4 HTML-formatted Telegram messages (wo_ready with tracking link, payment,
  appointment, reminder)

Service reminders:
- `reminders:send` artisan command with --slug / --dry-run
- Policy: vehicles whose last closed WO is older than reminder.after_days
  (default 365). Skips if sent within reminder.cooldown_days (default 30).
- Schedule daily 09:00

Filament UI:
- Settings page: Telegram bot token field + "Test bot" + "Set webhook" actions
- Settings page: reminder_after_days + reminder_cooldown_days inputs
- ClientResource: telegram_chat_id readonly badge

Tests (6 new, all pass):
- webhook links client via shared contact
- webhook rejects wrong secret → 401
- dispatcher uses telegram when chat_id present (Http::fake)
- dispatcher falls back to email otherwise
- dispatcher returns false when no channel available
- reminder cron respects 30-day cooldown

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

app/Filament/Tenant/Resources/ClientResource.php

@@ -73,6 +73,14 @@ class ClientResource extends Resource
                     Forms\Components\TextInput::make('phone_alt')->label('Telefon alternativ')->tel()->maxLength(40),
                     Forms\Components\TextInput::make('email')->email()->maxLength(120),
                     Forms\Components\TextInput::make('telegram')->maxLength(60),
+                    Forms\Components\TextInput::make('telegram_chat_id')
+                        ->label('Telegram chat ID')
+                        ->disabled()
+                        ->dehydrated(false)
+                        ->placeholder('Se completează automat când clientul scrie la bot')
+                        ->helperText(fn ($record) => $record?->telegram_chat_id
+                            ? '✅ Telegram legat — notificările vor merge prin bot'
+                            : null),
                     Forms\Components\TextInput::make('whatsapp')->maxLength(60),
                     Forms\Components\TextInput::make('viber')->maxLength(60),
                 ]),