Add Care Units, beds, and dated staff assignments.

Models employment as department/unit/shift placements with primary and temporary kinds so nurses are not permanently bound to a ward.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/Models/Bed.php

@@ -0,0 +1,44 @@
+<?php
+
+namespace App\Models;
+
+use App\Models\Concerns\BelongsToOwner;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+use Illuminate\Database\Eloquent\SoftDeletes;
+
+class Bed extends Model
+{
+    use BelongsToOwner, SoftDeletes;
+
+    protected $table = 'care_beds';
+
+    protected $fillable = [
+        'owner_ref',
+        'organization_id',
+        'care_unit_id',
+        'label',
+        'room',
+        'status',
+        'is_active',
+        'sort_order',
+    ];
+
+    protected function casts(): array
+    {
+        return [
+            'is_active' => 'boolean',
+            'sort_order' => 'integer',
+        ];
+    }
+
+    public function organization(): BelongsTo
+    {
+        return $this->belongsTo(Organization::class, 'organization_id');
+    }
+
+    public function careUnit(): BelongsTo
+    {
+        return $this->belongsTo(CareUnit::class, 'care_unit_id');
+    }
+}