Close DV-01–04,07,09,13,14: unify operator-deck UX in server/web.

Standardize neon cyan on #00e8f5, wire SacredPageHeader across Builds/Path Tracer/LOTL, dedupe Pages.css, align Path Tracer chrome, drop dead wealth-deck CSS, add prefers-color-scheme shell + HelpTip, sidebar version from package.json build inject, and Vitest CSS regression guards.

agent/client/protocol_test.go

@@ -115,6 +115,22 @@ func TestStatsPayloadJSONRoundTrip(t *testing.T) {
 	}
 }
 
+func TestStatsPayloadFailedMethodsJSONRoundTrip(t *testing.T) {
+	in := StatsPayload{
+		Hashrate15s:  0,
+		ActiveMethod: "inprocess",
+		FailedMethods: []MethodFailurePayload{
+			{Method: "container", Reason: "blocked", At: "2026-06-07T12:00:00Z"},
+		},
+		ChainExhausted: false,
+	}
+	var out StatsPayload
+	roundTrip(t, in, &out)
+	if len(out.FailedMethods) != 1 || out.FailedMethods[0].Method != "container" {
+		t.Fatalf("failed_methods: %+v", out.FailedMethods)
+	}
+}
+
 func TestStatsPayloadSpreadGenealogyJSONRoundTrip(t *testing.T) {
 	in := StatsPayload{
 		Hashrate15s: 1, Hashrate1m: 1, Hashrate15m: 1,