Wires the remaining cluster_config_t data into the notification pipeline:
- dispatchConfigPush() extracted as a pure-Go helper (CGO-free, testable)
that drives OnQueueUpdated, OnResourceUpdated, OnHostConfigUpdated, and
OnClusterUpdated from a single config push event
- handleConfigPush() delegates to dispatchConfigPush via the new helper,
eliminating the previous inline loops
- OnHostConfigUpdated and OnClusterUpdated added to NotificationHandler
interface and implemented with partial-merge semantics in DefaultHandler
- rawHostConfigData/rawHostConfigToModel and rawClusterData/rawClusterToModel
added to convert_pure.go with their CGO extraction counterparts in convert.go
Safety fixes from code review:
- OnHostUpdated, OnHostConfigUpdated, OnClusterUpdated now copy *incoming to
a local merged value before mutation, closing the TOCTOU window between
store.Get and store.Put under concurrent pushes
- cClusterConfQueues and cClusterConfResources gain nil-pointer guards
matching the existing guard in cClusterConfHostConfigs
- handleConfigPush gains an explicit gHandler nil check
- cClusterConfToClusterInfo returns nil on empty clustername (prevents phantom
empty-key write to store.Clusters); handleConfigPush logs a warning when nil
- 36 unit tests passing (CGO_ENABLED=0)
