fix(usage): require API v6 for remote rollups

API v5 shipped before combined subagent usage, so accepting it can silently return own-session totals. Advance the daemon contract and reject that predecessor before synchronization or usage requests.

Author: wesm

cmd/agentsview/session_test.go

@@ -1291,7 +1291,7 @@ func TestSessionUsage_ServerFlagRejectsCombinedUsageFromOlderDaemon(
 
 	ts, reqs := newRemoteUsageServer(t, remoteUsageSpec{
 		canonicalID: "remote-session",
-		apiVersion:  4,
+		apiVersion:  5,
 	})
 	cmd := sessionUsageCommand(t,
 		"session", "usage", "remote-session", "--server", ts.URL)

internal/server/server.go

@@ -47,10 +47,10 @@ type VersionInfo struct {
 // Bump it when a client-visible contract cannot be decoded safely by an older
 // CLI or daemon.
 const (
-	APIVersion = 5
+	APIVersion = 6
 	// SubagentUsageAPIVersion is the first daemon API that guarantees
 	// combined session-usage scope and targeted descendant synchronization.
-	SubagentUsageAPIVersion = 5
+	SubagentUsageAPIVersion = 6
 )
 
 const daemonService = "agentsview"