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.

server/internal/db/sqlite_test.go

@@ -64,6 +64,36 @@ func TestGetAgentNotFound(t *testing.T) {
 	}
 }
 
+func TestUpsertAgentPreservesOperatorNameWhenDiffersFromHostname(t *testing.T) {
+	d := openTestDB(t)
+	a := &models.Agent{
+		ID:       "renamed-worker",
+		Name:     "Living Room PC",
+		Hostname: "DESKTOP-ABC123",
+		Status:   "offline",
+		LastSeen: time.Now(),
+	}
+	if err := d.UpsertAgent(a); err != nil {
+		t.Fatal(err)
+	}
+
+	// Reconnect reports hostname only — UpsertAgent must keep operator label.
+	a.Name = "DESKTOP-ABC123"
+	a.Hostname = "DESKTOP-ABC123"
+	a.Status = "online"
+	if err := d.UpsertAgent(a); err != nil {
+		t.Fatal(err)
+	}
+
+	got, err := d.GetAgent(a.ID)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got.Name != "Living Room PC" {
+		t.Fatalf("operator name should be preserved; got %q hostname=%q", got.Name, got.Hostname)
+	}
+}
+
 func TestUpsertAgentPreservesCreatedAt(t *testing.T) {
 	d := openTestDB(t)
 	a := seedAgent(t, d, "persist-created")