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>

database/migrations/2026_05_27_180000_add_notification_channels.php

@@ -0,0 +1,39 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    public function up(): void
+    {
+        Schema::table('clients', function (Blueprint $t) {
+            $t->string('telegram_chat_id', 32)->nullable()->after('telegram');
+            $t->json('notify_prefs')->nullable()->after('telegram_chat_id');
+            $t->index(['company_id', 'telegram_chat_id']);
+        });
+
+        Schema::create('service_reminders_sent', function (Blueprint $t) {
+            $t->id();
+            $t->foreignId('company_id')->constrained()->cascadeOnDelete();
+            $t->foreignId('vehicle_id')->constrained()->cascadeOnDelete();
+            $t->foreignId('client_id')->nullable()->constrained()->nullOnDelete();
+            $t->string('channel', 16);    // email / telegram
+            $t->string('type', 24)->default('general'); // general / inspection / oil / etc
+            $t->dateTime('sent_at');
+            $t->timestamps();
+
+            $t->index(['company_id', 'vehicle_id', 'sent_at']);
+        });
+    }
+
+    public function down(): void
+    {
+        Schema::dropIfExists('service_reminders_sent');
+        Schema::table('clients', function (Blueprint $t) {
+            $t->dropIndex(['company_id', 'telegram_chat_id']);
+            $t->dropColumn(['telegram_chat_id', 'notify_prefs']);
+        });
+    }
+};