refactor: Add getters for protected model properties

- Create BaseModel with getters for $table, $primaryKey, $allowedFields
- All models now extend BaseModel instead of CodeIgniter\Model
- Add type declarations to protected properties

Closes #4489

app/Models/BaseModel.php

@@ -0,0 +1,33 @@
+<?php
+
+namespace App\Models;
+
+use CodeIgniter\Model;
+
+abstract class BaseModel extends Model
+{
+    public function getTableName(): string
+    {
+        return $this->table;
+    }
+
+    public function getPrimaryKeyName(): string
+    {
+        return $this->primaryKey;
+    }
+
+    public function getAllowedFields(): array
+    {
+        return $this->allowedFields;
+    }
+
+    public function getUseAutoIncrement(): bool
+    {
+        return $this->useAutoIncrement;
+    }
+
+    public function getUseSoftDeletes(): bool
+    {
+        return $this->useSoftDeletes;
+    }
+}