# PROGRESS.md — eng-pad-server Implementation Progress

This file tracks completed work and decisions. Updated after every step.
See PROJECT_PLAN.md for the full step list.

## Completed

_(none yet)_

## In Progress

Phase 0: Project Setup

## Decisions

- **Language**: Go (Metacircular standard)
- **Database**: SQLite via `modernc.org/sqlite` (pure Go, no CGo)
- **Auth**: Argon2id passwords + FIDO2/U2F via `go-webauthn/webauthn`
- **gRPC auth**: username/password in metadata per-request (no tokens)
- **Web auth**: password → bearer token in session cookie
- **Rendering**: SVG for web viewing, JPG/PDF for export
- **Sync model**: full notebook replacement (upsert), no incremental sync
- **Share links**: 32-byte random token, optional expiry, scoped to notebook
- **Grid**: not rendered server-side (tablet writing aid only)
- **Coordinate system**: 300 DPI canonical, scaled to 72 DPI for SVG/PDF
- **FIDO2/U2F**: web UI login only, not gRPC sync
- **Server is read-only**: mirrors tablet exactly, no content modification