Add playwright-cli config for isolated browsing and origin restrictions (#2417)

Follows the agentic browsing policy: uses isolated mode (fresh profile)
and restricts allowed origins to localhost only.

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: noisysocks

.playwright/cli.config.json

@@ -0,0 +1,13 @@
+{
+  "browser": {
+    "isolated": true
+  },
+  "network": {
+    "allowedOrigins": [
+      "https://localhost:*",
+      "http://localhost:*",
+      "https://127.0.0.1:*",
+      "http://127.0.0.1:*"
+    ]
+  }
+}