feat(qbz-slint): per-device-type icons in the QConnect device picker

Mirror Qobuz Connect's device icons in the connect flyout: map each renderer's
device_type to an icon (6 -> smartphone, 5 -> monitor or globe when the name is a
web player/browser, else -> speaker), matching the Tauri QconnectBadge
resolveDeviceType. Adds lucide monitor/smartphone/speaker/globe svgs, an icon key
on the QconnectDevice model computed in the event sink, and a per-row icon in the
PlayerBar device list.

cc

crates/qbz-slint/ui/assets/icons/globe.svg

@@ -0,0 +1,5 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="#ffffff" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+  <circle cx="12" cy="12" r="10" />
+  <path d="M12 2a14.5 14.5 0 0 0 0 20 14.5 14.5 0 0 0 0-20" />
+  <path d="M2 12h20" />
+</svg>

crates/qbz-slint/ui/assets/icons/monitor.svg

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+<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="#ffffff" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+  <rect width="20" height="14" x="2" y="3" rx="2" />
+  <line x1="8" x2="16" y1="21" y2="21" />
+  <line x1="12" x2="12" y1="17" y2="21" />
+</svg>

crates/qbz-slint/ui/assets/icons/smartphone.svg

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+<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="#ffffff" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+  <rect width="14" height="20" x="5" y="2" rx="2" ry="2" />
+  <path d="M12 18h.01" />
+</svg>

crates/qbz-slint/ui/assets/icons/speaker.svg

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+<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="#ffffff" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+  <rect width="16" height="20" x="4" y="2" rx="2" />
+  <circle cx="12" cy="14" r="4" />
+  <path d="M12 6h.01" />
+</svg>