fix(2.10.2): AfterInstall must be a no-namespace class

EspoCRM's extension installer (ExtensionManager.php → Base.php:397) does
require_once on scripts/AfterInstall.php and then `new AfterInstall()`
without any namespace prefix. The 2.10.0/2.10.1 version had
`namespace Espo\Modules\SmartAssistant\Scripts;` which resolved at
install time to "Class AfterInstall not found" and aborted the install
with HTTP 500 from KlearBrandingExtension/action/install.

Match the pattern used by GoogleIntegration/scripts/AfterInstall.php:
plain top-level class, no namespace, optional `use` for the Container
type hint. Same behavior (idempotent seed of 7 AssistantPrompt rows
with skipAll), just loadable.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

manifest.json

@@ -3,7 +3,7 @@
     "module": "SmartAssistant",
     "description": "Unified AI Assistant for Legal CRM — floating chat with case memory, office alerts, and AI Gateway integration",
     "author": "klear",
-    "version": "2.10.1",
+    "version": "2.10.2",
     "acceptableVersions": [
         ">=8.0.0"
     ],