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>

docs/reference/api/aigateway.md

@@ -121,6 +121,10 @@ Alias: also available at /api/v2/aibridge/sessions for backward compatibility.
       "models": [
         "string"
       ],
+      "network_calls": {
+        "blocked": 0,
+        "total": 0
+      },
       "providers": [
         "string"
       ],