Fix clientId parameter inconsistency in SSE endpoint

- Changed route parameter from 'clientId' to 'client_id' in McpController line 104
- This fixes the inconsistency where the Laravel controller expects 'client_id'
  but the SSE endpoint was generating URLs with 'clientId'
- Ensures consistency with OAuth standards and MCP client expectations

Author: micha

src/Http/Controllers/McpController.php

@@ -101,7 +101,7 @@ public function handleSse(Request $request): Response
             @set_time_limit(0);
 
             try {
-                $postEndpointUri = route('mcp.message', ['clientId' => $clientId], false);
+                $postEndpointUri = route('mcp.message', ['client_id' => $clientId], false);
 
                 $this->sendSseEvent('endpoint', $postEndpointUri, "mcp-endpoint-{$clientId}");
             } catch (Throwable $e) {