test(web): add playwright e2e for Dreams + docs screenshots

- packages/web/e2e/dreams.spec.ts: 4 tests covering sidebar entry,
  heading/breadcrumb resolution, mocked-API clustering into rows with
  count chips, and the premise-tree expansion path. Uses a function
  matcher for context.route so the trailing ?page=&page_size= query
  string doesn't break a glob.
- docs/screenshots/: dark + light mode list and expanded-detail PNGs
  captured at 2880x1800 (retina) via playwright against the dev
  server with a tiny mock Honcho.
- DreamList.tsx: add a literal space to CountChip's label fragment so
  the rendered text reads "3 explicit" instead of "3explicit" (gap-1
  styles the visual layout but doesn't add a text-node space). Better
  for screen readers, copy/paste, and assertion via toContainText.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

packages/web/src/components/dreams/DreamList.tsx

@@ -203,7 +203,7 @@ function CountChip({ label, value, kind }: { label: string; value: number; kind:
 			}}
 		>
 			<span>{value}</span>
-			<span className="hidden sm:inline">{label}</span>
+			<span className="hidden sm:inline"> {label}</span>
 		</span>
 	);
 }