📝 Changelog

Added: 75 new interactive simulations (15 per subject) — every one paired with realistic SVG laboratory apparatus.
Added: Lab Equipment Library — 36 vector SVG apparatus (beaker, flask, burner, microscope, thermometer, voltmeter, ammeter, battery, bulb, switch, resistor, burette, magnet, compass, pendulum, tripod, petri dish, telescope, pipette, funnel, plant, spring, trolley, inclined plane, pulley, lens, mirror, stopwatch, atom, DNA, heart, brain, volcano, planet, ...).
Added: Equipment Gallery page at /tools/equipment.html with search, subject filter and click-to-view modals.
Added: Every simulation page now shows the relevant equipment on a wooden virtual lab bench; clickable for details.
Added: Top bar now has a quick link to the Equipment Gallery; nav bar gains an "Equipment" item.
Added: Equipment Guide document at /docs/equipment-guide.html.
Updated: Manifest, service worker, PWA shortcuts, and sitemap to include the new pages.
Updated: Home page now showcases the equipment library and bench preview.
Preserved: Every v6 feature (periodic table, teacher dashboard, gamification, dark mode, backup/restore, etc.).
Performance: Equipment is SVG (text) — adds only a few KB, loads instantly on 2G.

Fixed periodic table, teacher pages, subject hubs.
Added 30 working sims, school admin dashboard, dark mode, equation solver, unit converter, full backup/restore.

Original release — 5 physics sims, partial periodic table.