Add support for Shelly device generation detection and update related tests

- Implement generation detection logic for Shelly devices using model codes, metadata, and type inference.
- Extend relay switch and inventory handling to include generation capabilities.
- Ensure compatibility with Gen1, Gen2, and Gen3 devices for relay control and diagnostics.
- Update unit tests to validate generation inference, fallback behavior, and API compatibility.

services/nginx/app/tests/Api/EdgeGatewayBrokerApiTest.php

@@ -132,6 +132,12 @@ it('validates broker sessions and ingests presence, telemetry, logs, and shell l
         ->assertEnvelope()
         ->assertSuccess();
 
+    expect($shellSession->data()['diagnostics'] ?? [])
+        ->toHaveKey('ready', true)
+        ->toHaveKey('reason_code', 'READY')
+        ->and($shellSession->data()['diagnostics']['broker_presence']['connection_id'] ?? null)
+        ->toBe('broker-presence-1');
+
     $shellToken = (string)$shellSession->data()['token'];
 
     $validateShell = api_client()->post(
@@ -172,6 +178,9 @@ it('validates broker sessions and ingests presence, telemetry, logs, and shell l
             'token' => $shellToken,
             'transcript' => "edge-broker-shell\n",
             'reason' => 'agent_exit',
+            'message' => 'Shell exited cleanly.',
+            'code' => 0,
+            'stage' => 'shell_active',
         ],
         edge_test_broker_headers()
     );
@@ -184,7 +193,15 @@ it('validates broker sessions and ingests presence, telemetry, logs, and shell l
     expect($closedShell->data())
         ->toHaveKey('status', 'COMPLETED')
         ->and($closedShell->data()['transcript'] ?? null)
-        ->toBe("edge-broker-shell\n");
+        ->toBe("edge-broker-shell\n")
+        ->and($closedShell->data()['metadata']['close_reason'] ?? null)
+        ->toBe('agent_exit')
+        ->and($closedShell->data()['metadata']['close_message'] ?? null)
+        ->toBe('Shell exited cleanly.')
+        ->and($closedShell->data()['metadata']['close_code'] ?? null)
+        ->toBe(0)
+        ->and($closedShell->data()['metadata']['close_stage'] ?? null)
+        ->toBe('shell_active');
 
     $logsPage = api_client()->get('/edge-gateways/' . (int)$gateway['id'] . '/logs', $session['headers']);
 
@@ -214,6 +231,35 @@ it('validates broker sessions and ingests presence, telemetry, logs, and shell l
         ->toBe(0.42);
 });
 
+it('rejects shell session creation while broker presence is unavailable', function (): void {
+    $department = api_fixtures()->createDepartment([
+        'name' => 'Edge Broker Shell Readiness Department',
+    ]);
+    $session = api_fixtures()->createEdgeOperatorSession((int)$department['id']);
+    $gateway = api_fixtures()->createClaimedEdgeGateway([
+        'department_id' => (int)$department['id'],
+        'label' => 'Disconnected Broker Gateway',
+    ]);
+
+    $response = api_client()->post(
+        '/edge-gateways/' . (int)$gateway['id'] . '/shell-sessions',
+        ['reason' => 'Should fail without broker presence'],
+        $session['headers']
+    );
+
+    $response
+        ->assertStatus(409)
+        ->assertEnvelope()
+        ->assertSuccess(false);
+
+    expect($response->data())
+        ->toHaveKey('error_code', 'BROKER_DISCONNECTED')
+        ->and($response->data()['diagnostics']['ready'] ?? true)
+        ->toBeFalse()
+        ->and($response->data()['diagnostics']['broker_presence']['connected'] ?? true)
+        ->toBeFalse();
+});
+
 it('builds broker backlog and completes gateway operations through broker endpoints', function (): void {
     $department = api_fixtures()->createDepartment([
         'name' => 'Edge Broker Backlog Department',