LearnSpace: full-stack educational whiteboard platform

Node.js/Express backend + vanilla JS frontend.
Features: real-time collaborative whiteboard (SSE), multi-page support,
LaTeX formulas, shapes/connectors, coordinate systems, number lines,
compass, zoom/pan, Catmull-Rom pencil smoothing, ruler/protractor with
rotation & resize controls, minimap navigation overlay, auto-measurements,
multi-page thumbnails sidebar, PNG export, page templates.
Student/teacher workflows: classes, assignments, library, dashboard.
Mobile responsive. SQLite (better-sqlite3).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/src/routes/biochem.js

@@ -0,0 +1,18 @@
+const router = require('express').Router();
+const { authMiddleware } = require('../middleware/auth');
+const c = require('../controllers/biochemController');
+
+router.use(authMiddleware);
+
+router.get('/elements',               c.getElements);
+router.get('/molecules',              c.getMolecules);
+router.get('/molecules/:id',          c.getMolecule);
+router.post('/validate',              c.validate);
+router.get('/reactions',              c.getReactions);
+router.get('/challenges',             c.getChallenges);
+router.post('/challenges/:id/solve',  c.solveChallenge);
+router.get('/saved',                  c.getSaved);
+router.post('/saved',                 c.saveMolecule);
+router.delete('/saved/:id',           c.deleteSaved);
+
+module.exports = router;