web topo: merge identical node-set clusters into one frame with side-by-side chips, stagger frame bottoms by nest rank, draw all frames before all chips (no border strikes through labels)

src/web/ui.playwright.mjs

@@ -310,7 +310,7 @@ ok(
 await page.evaluate(() => {
   for (const w of document.querySelectorAll(".win")) if (w.id !== "win-topo") w.style.display = "none";
 });
-await page.click('#topo [data-cluster="fake2"] .fchip');
+await page.click('#topo .fchip[data-cluster="fake2"]');
 await page.waitForFunction(
   () => document.querySelector("#clusters .chip.active")?.textContent?.includes("fake2"),
   { timeout: 5000 },