fix(web): TrackMenuItem icon prop accepts Lucide class-components

svelte-check on the new dev-push CI surfaced 11 type errors. Cause:
TrackMenuItem typed `icon` as Svelte 5's runes-mode `Component<...>`,
but Lucide-svelte ships class-based components whose type is
`ComponentType<SvelteComponent<...>>`. Switch the prop type to match
Lucide's actual export shape.

Also drop the redundant role="separator" on TrackMenuDivider — <hr>
already implies role=separator (svelte-check warning).

The remaining a11y warnings (tabindex on role=menu/dialog elements,
key-handler-with-click) are pre-existing in FlagPopover and surface
on the new dev-push run because svelte-check now sees them. They're
warnings not errors, so they don't block CI; address as a follow-up.

web/src/lib/components/TrackMenuDivider.svelte

@@ -1 +1 @@
-<hr class="my-1 border-border" role="separator" />
+<hr class="my-1 border-border" />

web/src/lib/components/TrackMenuItem.svelte

@@ -1,5 +1,12 @@
 <script lang="ts">
-  import type { Component } from 'svelte';
+  import type { ComponentType, SvelteComponent } from 'svelte';
+
+  // Lucide-svelte ships class-based components (typeof ListPlus = ComponentType<...>),
+  // not runes-mode function components (Svelte 5's Component<...> type). Use
+  // ComponentType<SvelteComponent<...>> so any Lucide icon assigns cleanly.
+  type IconProp = ComponentType<
+    SvelteComponent<{ size?: number; strokeWidth?: number; class?: string }>
+  >;
 
   let {
     icon,
@@ -9,8 +16,8 @@
     danger = false,
     title,
   }: {
-    /** Lucide icon component (or any Svelte component matching the Lucide signature). */
-    icon: Component<{ size?: number; strokeWidth?: number; class?: string }>;
+    /** Lucide icon component (or any Svelte class-component matching the Lucide signature). */
+    icon: IconProp;
     label: string;
     onclick?: () => void;
     disabled?: boolean;