fix: remove Model/Setting constructors that broke sandbox connection switching

The constructors introduced in both Model.php and Setting.php called:

    $this->connection = config('fleetbase.db.connection');

This config key does not exist (correct key: fleetbase.connection.db),
so config() returned null, overwriting the child class's declared
$connection property on every instantiation.

A subsequent attempt to guard with empty($this->connection) overcorrected
in the opposite direction: models without an explicit $connection
declaration (the sandbox-aware ones) were always resolved to 'mysql',
ignoring the database.default switch that sandbox mode sets to 'sandbox'.

The correct fix is simply to remove both constructors entirely:

- PHP initialises class property declarations before any constructor runs,
  so models that explicitly declare $connection = 'mysql' (Invite, Setting,
  User, Company, Role, Permission, etc.) will always use that value — no
  constructor logic needed.

- Models that do NOT declare $connection (ApiCredential, CompanyUser,
  Activity, etc.) correctly inherit null from Eloquent's base class, which
  causes Laravel to resolve the connection from config('database.default').
  In sandbox mode that is 'sandbox'; in normal mode it is 'mysql'. This is
  exactly the intended behaviour.

No functional change for any model — this purely restores the correct
connection resolution that existed before the constructors were added.

Author: Ronald A Richardson

src/Models/Model.php

@@ -30,35 +30,6 @@ class Model extends EloquentModel
     public const UUID_COLUMN      = 'uuid';
     public const PUBLIC_ID_COLUMN = 'public_id';
 
-    /**
-     * Create a new instance of the model.
-     *
-     * @param array $attributes the attributes to set on the model
-     *
-     * @return void
-     */
-    public function __construct(array $attributes = [])
-    {
-        parent::__construct($attributes);
-
-        // Resolve the configured production DB connection name.
-        // The correct config key is `fleetbase.connection.db`; the previously
-        // used key `fleetbase.db.connection` was a typo that returned null,
-        // causing every model to silently fall back to `database.default`.
-        // When sandbox mode is active `database.default` is switched to
-        // `sandbox`, which meant models with an explicit `$connection = 'mysql'`
-        // (e.g. Invite) were still written to the sandbox database because the
-        // parent constructor overwrote the child's property with null.
-        //
-        // Only apply the override when the child class has NOT declared its own
-        // explicit $connection, so models that intentionally pin themselves to
-        // a specific connection (e.g. `protected $connection = 'mysql'`) are
-        // left untouched.
-        if (empty($this->connection)) {
-            $this->connection = config('fleetbase.connection.db', config('database.connections.mysql') ? 'mysql' : config('database.default'));
-        }
-    }
-
     /**
      * The primary key for the model.
      *

src/Models/Setting.php

@@ -20,27 +20,6 @@ class Setting extends EloquentModel
     use Searchable;
     use Filterable;
 
-    /**
-     * Create a new instance of the model.
-     *
-     * @param array $attributes the attributes to set on the model
-     *
-     * @return void
-     */
-    public function __construct(array $attributes = [])
-    {
-        parent::__construct($attributes);
-
-        // Settings must always read/write from the production database.
-        // Do not overwrite the explicit $connection = 'mysql' declared below;
-        // the previously used config key `fleetbase.db.connection` was a typo
-        // (correct key: `fleetbase.connection.db`) that returned null and caused
-        // this model to silently follow `database.default` into the sandbox DB.
-        if (empty($this->connection)) {
-            $this->connection = config('fleetbase.connection.db', 'mysql');
-        }
-    }
-
     /**
      * No timestamp columns.
      *