collections: add AI Gateways (10142) — 13 verified high-quality repos

Replaces the original PR #1898 which had 3000+ garbage repos.
- Only includes repos with 500+ stars
- All verified to exist via GitHub API
- No ID conflicts (uses 10142)
- Removed llm-gateways and mcp-gateways (overlap with existing 10115, 10099, 10105)

Author: sykp241095

configs/collections/10142.ai-gateways.yml

@@ -0,0 +1,16 @@
+id: 10142
+name: AI Gateways
+items:
+  - Kong/kong
+  - apache/apisix
+  - alibaba/higress
+  - BerriAI/litellm
+  - Portkey-AI/gateway
+  - envoyproxy/ai-gateway
+  - krakend/krakend-ce
+  - APIParkLab/APIPark
+  - Helicone/ai-gateway
+  - agentgateway/agentgateway
+  - maximhq/bifrost
+  - NeuralTrust/TrustGate
+  - EinStack/glide