docs: update AGENTS.md hierarchy with new subdirectory docs

- Update root AGENTS.md with expanded anti-patterns and notes
- Add handler/AGENTS.md for high-complexity backend handlers
- Add connector/AGENTS.md for GOST connector protocols
- Add socket/AGENTS.md for GOST socket utilities

go-gost/x/socket/AGENTS.md

@@ -0,0 +1,30 @@
+# GOST SOCKET KNOWLEDGE BASE
+
+**Generated:** Fri Feb 13 2026
+
+## OVERVIEW
+Socket utilities and wrappers for GOST forwarding.
+**Stack:** Go, GOST core.
+
+## STRUCTURE
+```
+socket/
+├── socket.go      # Core socket interface
+├── udp.go         # UDP socket handling
+├── packet.go      # Packet framing
+├── packetconn.go  # Packet connection wrapper
+└── ...            # Additional socket utilities
+```
+
+## CONVENTIONS
+- Inherits from parent `go-gost/x/` conventions.
+- Low-level network primitives.
+
+## ANTI-PATTERNS
+- DO NOT EDIT generated protobuf.
+
+## COMMANDS
+```bash
+cd go-gost
+go test ./x/socket/...
+```