Add form conventions man page and CLAUDE.md documentation

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

docs/CLAUDE.dist.md

@@ -891,6 +891,39 @@ class My_Form extends Component {
 
 **Validation**: `Form_Utils.apply_form_errors(form.$, errors)` - Matches by `name` attribute.
 
+### Form Conventions (Action/Controller Pattern)
+
+Forms follow a load/save pattern mirroring traditional Laravel: Action loads data, Controller saves it.
+
+```javascript
+// Action: on_create() sets defaults, on_load() fetches for edit mode
+on_create() {
+    this.data.form_data = { title: '', status_id: Model.STATUS_ACTIVE };
+    this.data.is_edit = !!this.args.id;
+}
+async on_load() {
+    if (!this.data.is_edit) return;
+    const record = await My_Model.fetch(this.args.id);
+    this.data.form_data = { id: record.id, title: record.title };
+}
+```
+
+```php
+// Controller: save() receives all form values, validates, persists
+#[Ajax_Endpoint]
+public static function save(Request $request, array $params = []) {
+    if (empty($params['title'])) return response_form_error('Error', ['title' => 'Required']);
+    $record = $params['id'] ? My_Model::find($params['id']) : new My_Model();
+    $record->title = $params['title'];
+    $record->save();
+    return ['redirect' => Rsx::Route('View_Action', $record->id)];
+}
+```
+
+**Key principles**: form_data must be serializable (plain objects, no models) | Keep load/save in same controller for field alignment | on_load() loads data, on_ready() is UI-only
+
+Details: `php artisan rsx:man form_conventions`
+
 ---
 
 ## MODALS