Replaced inline symbolic characters with Lucide icons

Replaced all inline symbolic characters in Svelte components with their Lucide icon equivalents:

• ↗ → ExternalLink (external links)
• ← → ArrowLeft (back buttons)
• → → ArrowRight (forward/continue buttons)
• ♥ → Heart (support links)
• ✓ → Check (completion indicators)
• ☰ → Menu (hamburger menu references)

Also removed redundant ✓/✗ from pds-landing StatusGrid (the status styling handles it) and replaced the CSS ::before arrow in LinkList with ›.

Left instructional → in prose (e.g. "Tap menu → Settings → Accounts") unchanged — those are navigation breadcrumbs in text, not UI elements.