feat: add network calls column to AI sessions table (#27269)

Add a "Total/blocked network calls" column to the AIBridge sessions
table.

Update `ListAIBridgeSessions` query to calculate network called made and
blocked per session. See query plan
[here](https://explain.dalibo.com/plan/54355c90b165ggb4).

---------

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

coderd/apidoc/swagger.json

@@ -13598,6 +13598,14 @@
 						"type": "string"
 					}
 				},
+				"network_calls": {
+					"description": "NetworkCalls summarizes the Agent Firewall network calls made during the\nsession. A nil value means the session did not pass through Agent\nFirewall, so network call monitoring was not active, which the UI\nsurfaces as \"Disabled\".",
+					"allOf": [
+						{
+							"$ref": "#/definitions/codersdk.AIBridgeSessionNetworkCallSummary"
+						}
+					]
+				},
 				"providers": {
 					"type": "array",
 					"items": {
@@ -13616,6 +13624,17 @@
 				}
 			}
 		},
+		"codersdk.AIBridgeSessionNetworkCallSummary": {
+			"type": "object",
+			"properties": {
+				"blocked": {
+					"type": "integer"
+				},
+				"total": {
+					"type": "integer"
+				}
+			}
+		},
 		"codersdk.AIBridgeSessionThreadsResponse": {
 			"type": "object",
 			"properties": {