fix border resizing ui

tests/scratch-hover.test.tsx

@@ -0,0 +1,59 @@
+/** Scratch — verify full-height hover accent line. */
+import { test, expect } from "bun:test";
+import { testRender } from "@opentui/solid";
+import { ThemeProvider } from "../src/context/ThemeContext";
+import { PaneRow } from "../src/components/PaneRow";
+import { mkdtempSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+
+process.env.XDG_CONFIG_HOME = mkdtempSync(join(tmpdir(), "podtui-phover3-"));
+
+type Span = { text: string; fg?: { r: number; g: number; b: number; a: number } | null };
+type Frame = { cols: number; lines: { spans: Span[] }[] };
+
+test("hover renders accent line on every row", async () => {
+	const setup = (await testRender(
+		() => (
+			<ThemeProvider mode="dark">
+				<PaneRow
+					parent={<text selectable={false}>{"P".repeat(300)}</text>}
+					current={<text selectable={false}>{"C".repeat(600)}</text>}
+					preview={<text selectable={false}>{"V".repeat(300)}</text>}
+					currentLabel=""
+				/>
+			</ThemeProvider>
+		),
+		{ width: 100, height: 10, useThread: false },
+	)) as unknown as {
+		renderOnce: () => Promise<void>;
+		captureSpans: () => Frame;
+		captureCharFrame: () => string;
+		mockMouse: { moveTo: (x: number, y: number) => Promise<void> };
+		renderer: { destroy: () => void };
+	};
+	for (let i = 0; i < 10; i++) await setup.renderOnce();
+	await setup.mockMouse.moveTo(20, 5);
+	for (let i = 0; i < 3; i++) await setup.renderOnce();
+
+	const frame = setup.captureSpans();
+	let accentRows = 0;
+	for (let y = 0; y < frame.lines.length; y++) {
+		const line = frame.lines[y].spans.map((s) => s.text).join("");
+		// Border column = 20.
+		const ch = line[20];
+		const isAccent = frame.lines[y].spans
+			.filter((s) => s.text.length > 0)
+			.some((s) => {
+				const t = s.text;
+				let c = 0;
+				// recompute col: approximate by scanning previous spans
+				return false;
+			});
+		if (ch === "│") accentRows++;
+		console.log(`row ${y}: ${JSON.stringify(line.slice(16, 25))} ch20=${JSON.stringify(ch)}`);
+	}
+	console.log("accentRows:", accentRows, "of", frame.lines.length);
+	expect(accentRows).toBeGreaterThanOrEqual(6);
+	setup.renderer.destroy();
+});