initial commit: Artifacto v0.1

Self-hosted HTML artifact publisher. Single Go binary, SQLite metadata,
HTML on disk. Features: password-protected artifacts, per-artifact expiration,
admin dashboard with view metrics (privacy-preserving daily-salt visitor hash,
sparklines, 30-day SVG chart, top referrers), rate-limited unlock endpoint.

Packaged as a Docker image (two-stage, CGO_ENABLED=0, pure-Go SQLite).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

README.md

@@ -0,0 +1,39 @@
+# Artifacto
+
+Self-hosted drop-and-share for HTML artifacts. Paste HTML → get a link → share.
+Single-binary Go service, SQLite metadata, HTML bodies on disk, behind a reverse proxy.
+
+## Features
+
+- Paste or upload HTML, auto-generated slug (or custom)
+- Optional per-artifact password (bcrypt), rate-limited unlock
+- Optional expiration (time or view-count)
+- Admin dashboard with view counts, sparklines, per-artifact 30-day chart
+- Privacy-preserving visitor hash (daily-rotated salt, no cookies on viewers)
+- One container, one SQLite file, one data directory
+
+## Quick start
+
+```bash
+cp .env.example .env           # set ADMIN_PASSWORD + SESSION_SECRET
+docker compose up -d
+open http://localhost:3100
+```
+
+Then put a reverse proxy (Caddy, nginx, Traefik) in front for HTTPS.
+
+## Configuration
+
+| Env var          | Default                              | Purpose                             |
+|------------------|--------------------------------------|-------------------------------------|
+| `ADMIN_PASSWORD` | — (required)                         | Admin login password                |
+| `SESSION_SECRET` | — (required, 32+ bytes hex)          | Cookie HMAC key                     |
+| `BASE_URL`       | `http://localhost:3000`              | Used when building share links      |
+| `DATA_DIR`       | `/data`                              | SQLite DB + artifact files          |
+| `BIND_ADDR`      | `:3000`                              | Listen address                      |
+| `MAX_UPLOAD_MB`  | `5`                                  | Per-artifact upload cap             |
+| `LOG_LEVEL`      | `info`                               | `info` or `debug`                   |
+
+## License
+
+MIT