[client] UI refactor (#6069)

Refactor UI

---------

Co-authored-by: Eduard Gert <kontakt@eduardgert.de>
Co-authored-by: braginini <bangvalo@gmail.com>
Co-authored-by: Pascal Fischer <32096965+pascal-fischer@users.noreply.github.com>
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: riccardom <riccardomanfrin@gmail.com>

client/ui/tray_theme_linux_test.go

@@ -0,0 +1,86 @@
+//go:build linux && !(linux && 386)
+
+package main
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestReadKdeComplementaryBackground(t *testing.T) {
+	// Mirrors the KDE test VM's kdeglobals: Window light, Complementary dark.
+	// The tray sits on the panel, which Plasma paints from Complementary, so
+	// the panel is dark even though the global color-scheme is Light.
+	content := `[Colors:Window]
+BackgroundNormal=239,240,241
+
+[Colors:Complementary]
+BackgroundAlternate=27,30,32
+BackgroundNormal=42,46,50
+
+[General]
+ColorSchemeHash=0be804dba87e3512aeb4be3d78ed981f59f0f2f4
+`
+	path := filepath.Join(t.TempDir(), "kdeglobals")
+	if err := os.WriteFile(path, []byte(content), 0o600); err != nil {
+		t.Fatal(err)
+	}
+
+	rgb, ok := readKdeComplementaryBackground(path)
+	if !ok {
+		t.Fatal("expected to find Complementary BackgroundNormal")
+	}
+	if rgb != [3]uint8{42, 46, 50} {
+		t.Fatalf("rgb = %v, want [42 46 50]", rgb)
+	}
+	if !isDarkRGB(rgb[0], rgb[1], rgb[2]) {
+		t.Fatal("panel colour 42,46,50 should be dark")
+	}
+	// The Window background (what color-scheme reflects) is light — the bug
+	// this fix addresses is picking the icon from that instead of the panel.
+	if isDarkRGB(239, 240, 241) {
+		t.Fatal("window colour 239,240,241 should be light")
+	}
+}
+
+func TestReadKdeComplementaryBackgroundMissingGroup(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "kdeglobals")
+	if err := os.WriteFile(path, []byte("[Colors:Window]\nBackgroundNormal=1,2,3\n"), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	if _, ok := readKdeComplementaryBackground(path); ok {
+		t.Fatal("expected not-ok when Complementary group is absent")
+	}
+}
+
+func TestParseRGB(t *testing.T) {
+	if _, ok := parseRGB("1,2"); ok {
+		t.Fatal("two components should fail")
+	}
+	if _, ok := parseRGB("300,0,0"); ok {
+		t.Fatal("out-of-range should fail")
+	}
+	if _, ok := parseRGB("a,b,c"); ok {
+		t.Fatal("non-numeric should fail")
+	}
+	rgb, ok := parseRGB(" 10 , 20 , 30 ")
+	if !ok || rgb != [3]uint8{10, 20, 30} {
+		t.Fatalf("parseRGB = %v ok=%v, want [10 20 30] true", rgb, ok)
+	}
+}
+
+func TestIsDarkRGB(t *testing.T) {
+	if !isDarkRGB(0, 0, 0) {
+		t.Fatal("black is dark")
+	}
+	if isDarkRGB(255, 255, 255) {
+		t.Fatal("white is light")
+	}
+	if !isDarkRGB(42, 46, 50) {
+		t.Fatal("Breeze panel grey is dark")
+	}
+	if isDarkRGB(239, 240, 241) {
+		t.Fatal("Breeze window grey is light")
+	}
+}