[client] Extract pure evalConnStatus and add unit tests

Split isConnectedOnAllWay into a thin method that snapshots state and
a pure evalConnStatus helper that takes a connStatusInputs struct, so
the tri-state decision logic can be exercised without constructing
full Worker or Handshaker objects. Add table-driven tests covering
force-relay, ICE-unavailable and fully-available code paths, plus
unit tests for iceRetryState budget/hourly transitions and reset.

client/internal/peer/conn_status.go

@@ -13,6 +13,20 @@ const (
 	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.
+type connStatusInputs struct {
+	forceRelay          bool // NB_FORCE_RELAY or JS/WASM
+	peerUsesRelay       bool // remote peer advertises relay support AND local has relay
+	relayConnected      bool // statusRelay reports Connected (independent of whether peer uses relay)
+	remoteSupportsICE   bool // remote peer sent ICE credentials
+	iceWorkerCreated    bool // local WorkerICE exists (false in force-relay mode)
+	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