fix: add missing fields to protobuf agent conversions

[amir20]

Summary

• APIKey, Prefix, and ExpiresAt missing from NotificationDispatcher protobuf message — dispatchers with API key auth, prefixes, or expiration silently broken on agent nodes
• ActorAttributes missing from ContainerEvent protobuf message — container renames and event-based notification attributes (including exit codes) lost on agent nodes
• NetworkRxTotal and NetworkTxTotal missing from ContainerStat in ToProto()/FromProto() — network metrics lost when syncing container data via agents

Same class of bug as #4563 — fields present in Go structs but omitted during protobuf conversion.

Test plan

• All existing Go and frontend tests pass
• Deploy in swarm mode, verify network stats appear for containers on agent nodes
• Create a dispatcher with API key/prefix/expiration, verify config reaches agent nodes
• Verify container rename events propagate from agent nodes
• Verify event-based alerts with exit code detection work on agent nodes

🤖 Generated with Claude Code

[claude]

Looks good. Fix is correct — APIKey, Prefix, and ExpiresAt in DispatcherConfig now properly round-trip through protobuf.

• client.go/server.go: symmetric conversion, nil-check on ExpiresAt is correct
• types.proto: field numbers 7-9, no conflicts
• Generated types.pb.go matches proto definition

No issues found.

[claude]

Confirmed correct fix. The networkRxTotal/networkTxTotal fields were already defined in the proto (fields 5-6 of ContainerStat) but never populated during conversion — silent data loss on agent nodes.

All three fixes are symmetric between client.go and server.go, and the nil-guard on ExpiresAt handles the optional timestamp correctly. No issues.