hscontrol/util/zlog/zf: add tag, authkey, and route constants

Add new zerolog field constants for improved logging consistency:

- Tag fields: CurrentTags, RemovedTags, RejectedTags, NewTags, OldTags,
  IsTagged, WasAuthKeyTagged
- Node fields: ExistingNodeID
- AuthKey fields: AuthKeyID, AuthKeyUsed, AuthKeyExpired, AuthKeyReusable,
  NodeKeyRotation
- Route fields: RoutesApprovedOld, RoutesApprovedNew, OldAnnouncedRoutes,
  NewAnnouncedRoutes, ApprovedRoutes, OldApprovedRoutes, NewApprovedRoutes,
  AutoApprovedRoutes, AllApprovedRoutes, RouteChanged

hscontrol/util/zlog/zf/fields.go

@@ -23,6 +23,7 @@ const (
 	NodeExpired        = "node.expired"
 	NodeHostname       = "node.hostname"
 	ExistingNodeName   = "existing.node.name"
+	ExistingNodeID     = "existing.node.id"
 	CurrentHostname    = "current_hostname"
 	RejectedHostname   = "rejected_hostname"
 	OldHostname        = "old_hostname"
@@ -36,6 +37,17 @@ const (
 	ExpiresAt          = "expiresAt"
 )
 
+// Tag fields for reauth and tag operations.
+const (
+	CurrentTags      = "current.tags"
+	RemovedTags      = "removed.tags"
+	RejectedTags     = "rejected.tags"
+	NewTags          = "new.tags"
+	OldTags          = "old.tags"
+	IsTagged         = "is.tagged"
+	WasAuthKeyTagged = "was.authkey.tagged"
+)
+
 // Machine fields.
 const (
 	MachineKey = "machine.key"
@@ -62,6 +74,11 @@ const (
 	PAKUsed         = "pak.used"
 	PAKIsTagged     = "pak.is_tagged"
 	PAKExpiration   = "pak.expiration"
+	AuthKeyID       = "authkey.id"
+	AuthKeyUsed     = "authkey.used"
+	AuthKeyExpired  = "authkey.expired"
+	AuthKeyReusable = "authkey.reusable"
+	NodeKeyRotation = "nodekey.rotation"
 )
 
 // APIKey fields.
@@ -76,6 +93,16 @@ const (
 const (
 	RoutesAnnounced    = "routes.announced"
 	RoutesApproved     = "routes.approved"
+	RoutesApprovedOld  = "routes.approved.old"
+	RoutesApprovedNew  = "routes.approved.new"
+	OldAnnouncedRoutes = "oldAnnouncedRoutes"
+	NewAnnouncedRoutes = "newAnnouncedRoutes"
+	ApprovedRoutes     = "approvedRoutes"
+	OldApprovedRoutes  = "oldApprovedRoutes"
+	NewApprovedRoutes  = "newApprovedRoutes"
+	AutoApprovedRoutes = "autoApprovedRoutes"
+	AllApprovedRoutes  = "allApprovedRoutes"
+	RouteChanged       = "routeChanged"
 	Prefix             = "prefix"
 	FinalState         = "finalState"
 	NewState           = "newState"