feat: group resources into rooms on the floor plan

src/Entity/Resource.php

@@ -34,6 +34,14 @@ class Resource
     #[ORM\Column(length: 50, nullable: true)]
     private ?string $svgElementId = null;
 
+    /**
+     * Where it physically is. Nullable because a group is optional: a kind of resource that is
+     * not split across rooms simply has none, and its plan draws its own single frame.
+     */
+    #[ORM\ManyToOne]
+    #[ORM\JoinColumn(nullable: true, onDelete: 'SET NULL')]
+    private ?ResourceGroup $group = null;
+
     /**
      * Retired resources stay in the table so historical bookings keep resolving; they are just
      * not offered any more.
@@ -78,6 +86,16 @@ class Resource
         $this->svgElementId = $svgElementId;
     }
 
+    public function getGroup(): ?ResourceGroup
+    {
+        return $this->group;
+    }
+
+    public function setGroup(?ResourceGroup $group): void
+    {
+        $this->group = $group;
+    }
+
     public function isActive(): bool
     {
         return $this->active;