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>

.gitignore

@@ -0,0 +1,29 @@
+# Dependencies
+node_modules/
+backend/node_modules/
+
+# Database files
+*.db
+*.db-shm
+*.db-wal
+data/
+
+# Environment / secrets
+.env
+.env.*
+!.env.example
+
+# Uploads
+backend/uploads/
+
+# Logs
+*.log
+server.log
+
+# OS
+.DS_Store
+Thumbs.db
+
+# Build artifacts
+dist/
+build/