Final sweep: Crucible fixes, Path Tracer polish, forge progress, tests green.

Align dashboard subtitle default and UpsertAgent tests with fleet label behavior; WebSocket coalesce and PathForge hardening; Crucible expanded ops and visual DV fixes; Vitest 610/610 and full test-suite pass; trim PROBLEMS.md to open items only.

server/config_test.go

@@ -50,7 +50,7 @@ func TestDefaultConfigServerDefaults(t *testing.T) {
 	if !cfg.Server.LogAgentConnections {
 		t.Fatal("log_agent_connections should default true")
 	}
-	if cfg.Server.DashboardSubtitle != "security is just an emotion" {
+	if cfg.Server.DashboardSubtitle != "Fleet Command & Control" {
 		t.Fatalf("dashboard subtitle default wrong: %q", cfg.Server.DashboardSubtitle)
 	}
 	if cfg.DefaultAgent.Threads != 4 {