[client] Extract peer status recorder into its own package

Move the Status recorder and its state types out of the peer package
into client/internal/peer/status, split by struct across recorder.go,
peer_state.go, full_status.go, events.go, notifier.go and route.go
instead of one 1600-line file. Rename the type Status -> Recorder
(NewRecorder already implied it; avoids status.Status stutter). Split
conn_status.go: the ConnStatus type and its constants move to the status
package, connStatusInputs stays with the peer event loop.

The peer package references the status package directly; a transitional
status_alias.go re-exports the moved symbols for the ~50 external callers
still using peer.Status/State/ConnStatus, to be removed once they are
migrated.

client/internal/peer/conn_status.go

@@ -1,18 +1,5 @@
 package peer
 
-import (
-	log "github.com/sirupsen/logrus"
-)
-
-const (
-	// StatusIdle indicate the peer is in disconnected state
-	StatusIdle ConnStatus = iota
-	// StatusConnecting indicate the peer is in connecting state
-	StatusConnecting
-	// StatusConnected indicate the peer is in connected state
-	StatusConnected
-)
-
 // connStatusInputs is the primitive-valued snapshot of the state that drives the
 // tri-state connection classification. Extracted so the decision logic can be unit-tested
 // without constructing full Worker/Handshaker objects.
@@ -25,20 +12,3 @@ type connStatusInputs struct {
 	iceStatusConnecting bool // statusICE is anything other than Disconnected
 	iceInProgress       bool // a negotiation is currently in flight
 }
-
-// ConnStatus describe the status of a peer's connection
-type ConnStatus int32
-
-func (s ConnStatus) String() string {
-	switch s {
-	case StatusConnecting:
-		return "Connecting"
-	case StatusConnected:
-		return "Connected"
-	case StatusIdle:
-		return "Idle"
-	default:
-		log.Errorf("unknown status: %d", s)
-		return "INVALID_PEER_CONNECTION_STATUS"
-	}
-}