Fix unreliable window resize on Linux with custom resize handles (#77)

src/lib/components/ResizeHandles.svelte

@@ -0,0 +1,69 @@
+<script lang="ts">
+	import { onMount } from 'svelte';
+	import { getCurrentWindow } from '@tauri-apps/api/window';
+	import { isMobile } from '$lib/platform';
+
+	type Dir =
+		| 'North' | 'South' | 'East' | 'West'
+		| 'NorthEast' | 'NorthWest' | 'SouthEast' | 'SouthWest';
+
+	// Resolved only on the client (onMount), so SSR/prerender never calls Tauri APIs.
+	let appWindow = $state<ReturnType<typeof getCurrentWindow> | null>(null);
+	let maximized = $state(false);
+
+	onMount(() => {
+		if (isMobile) return;
+		const win = getCurrentWindow();
+		appWindow = win;
+		const refresh = () => win.isMaximized().then((m) => (maximized = m)).catch(() => {});
+		refresh();
+		const unlisten = win.onResized(() => refresh());
+		return () => { unlisten.then((fn) => fn()); };
+	});
+
+	function start(e: MouseEvent, dir: Dir) {
+		if (e.button !== 0 || !appWindow) return;
+		e.preventDefault();
+		appWindow.startResizeDragging(dir);
+	}
+</script>
+
+{#if appWindow && !maximized}
+	<div class="resize-layer" aria-hidden="true">
+		<div class="rz rz-n" onmousedown={(e) => start(e, 'North')}></div>
+		<div class="rz rz-s" onmousedown={(e) => start(e, 'South')}></div>
+		<div class="rz rz-w" onmousedown={(e) => start(e, 'West')}></div>
+		<div class="rz rz-e" onmousedown={(e) => start(e, 'East')}></div>
+		<div class="rz rz-nw" onmousedown={(e) => start(e, 'NorthWest')}></div>
+		<div class="rz rz-ne" onmousedown={(e) => start(e, 'NorthEast')}></div>
+		<div class="rz rz-sw" onmousedown={(e) => start(e, 'SouthWest')}></div>
+		<div class="rz rz-se" onmousedown={(e) => start(e, 'SouthEast')}></div>
+	</div>
+{/if}
+
+<style>
+	/* Transparent overlay; only the strips capture events, the rest passes through. */
+	.resize-layer {
+		position: fixed;
+		inset: 0;
+		pointer-events: none;
+		z-index: 99999;
+	}
+
+	.rz {
+		position: fixed;
+		pointer-events: auto;
+	}
+
+	/* Edges, inset by the corner size so corners win at the corners. */
+	.rz-n { top: 0; left: 14px; right: 14px; height: 6px; cursor: ns-resize; }
+	.rz-s { bottom: 0; left: 14px; right: 14px; height: 6px; cursor: ns-resize; }
+	.rz-w { left: 0; top: 14px; bottom: 14px; width: 6px; cursor: ew-resize; }
+	.rz-e { right: 0; top: 14px; bottom: 14px; width: 6px; cursor: ew-resize; }
+
+	/* Corners: larger, reliable grab targets. */
+	.rz-nw { top: 0; left: 0; width: 14px; height: 14px; cursor: nwse-resize; }
+	.rz-ne { top: 0; right: 0; width: 14px; height: 14px; cursor: nesw-resize; }
+	.rz-sw { bottom: 0; left: 0; width: 14px; height: 14px; cursor: nesw-resize; }
+	.rz-se { bottom: 0; right: 0; width: 14px; height: 14px; cursor: nwse-resize; }
+</style>