Faza 3.1: CRM core — Leads, Deals, Appointments, Settings, Widgets, Users

Spatie Permission cu teams (team_foreign_key=company_id, teams=true):
- migrations create_permission_tables (model_has_roles cu company_id scope)
- HasRoles trait pe User
- ResolveTenant middleware setează permissions team_id la tenant.id
- Seed: 7 roluri default per tenant (admin/manager/receptionist/mechanic/parts_manager/accountant/marketer)

Module noi:
- Leads (cereri): name, phone, car/model, source, UTM, status, budget, assigned_to,
  acțiune "Convertește" → creează automat Client + Deal
- Deals (pipeline): client/vehicle, stage (8 stage-uri), price, source, lost_reason
- Posts + Appointments: post_id (boxă), master_id, date+time_start+time_end, status, color
- UserResource (tenant): CRUD users cu role/status/locale; canViewAny doar pentru admin

Custom Filament page "Setări" (tenant):
- Brand & contact (display_name, city, phone, email)
- Localizare (limba RO/RU/EN, currency, theme color picker)
- Servicii & tarif (labor_rate)
- Liste configurabile (services, cars) — păstrate în companies.settings JSON

Widgets dashboard:
- Tenant: StatsOverview (Clienți, Mașini, Cereri noi, Deal-uri active, Programări azi)
- Central: PlatformStats (Companii total/active/trial, Expiră în 7 zile)

Seed extins demo PSauto:
- 3 posturi (Pod 1/2/3 cu culori)
- 2 lead-uri demo (Alex Grosu Telegram, Irina Cojocaru WhatsApp)
- 3 deal-uri demo (BMW done, Audi in_work, Porsche agree)
- 2 programări (azi + mâine)

Filament v5 fixes:
- $navigationGroup type → string|UnitEnum|null (parent stricter signature)
- Toate resources noi au tipurile corecte

app/Models/Tenant/Post.php

@@ -0,0 +1,23 @@
+<?php
+
+namespace App\Models\Tenant;
+
+use App\Models\Concerns\BelongsToTenant;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\HasMany;
+
+class Post extends Model
+{
+    use BelongsToTenant;
+
+    protected $fillable = ['company_id', 'name', 'color', 'is_active', 'sort_order'];
+
+    protected $casts = [
+        'is_active' => 'boolean',
+    ];
+
+    public function appointments(): HasMany
+    {
+        return $this->hasMany(Appointment::class);
+    }
+}