¶Architecture

Rust backend (Yggdrasil) ↔ Svelte 5 frontend (crown) over the Elyra Framework's typed MessagePack bridge. The Rust binary embeds the built frontend and serves it from elyra://localhost.

elyra-sja/
├── src/
│   ├── main.rs        # App wiring only (~130 lines)
│   ├── app_paths.rs   # data dir, DB URL, migration staging, retention/vacuum
│   ├── http.rs        # one shared, pooled HTTP client + capped body reads
│   ├── seo.rs         # single-page analysis engine (GUI-free)
│   ├── pagespeed.rs   # Core Web Vitals via PageSpeed Insights
│   ├── crawl.rs       # site crawler (sitemap + BFS, robots, aggregation)
│   ├── fs_tools.rs    # sandboxed AI file tools + write confirmation
│   ├── license.rs     # offline license validation (ed25519 signature)
│   ├── secrets.rs     # macOS Keychain wrapper
│   └── <commands>     # settings, licensing, projects, reports, trends,
│                      # crawls, monitors, ai, export
├── migrations/        # SQLite migrations (0001–0008)
├── app/               # Vite + Svelte 5 frontend
│   └── src/
│       ├── App.svelte           # shell, nav, views, scheduler timer
│       ├── bindings.ts          # generated by `rata codegen` — do not edit
│       └── lib/                 # Report, SiteReport, Trends, Monitors,
│                                # Settings, Lock, ProjectDialog, Icon, …
├── scripts/           # icns, dmg, updater keygen/sign
├── vendor/elyra-framework   # the framework, as a git submodule
└── .github/workflows/release.yml

¶Commands (typed bridge)

Frontend calls Rust through the generated api.* facade. Groups:

• Analysis — analyze_page, analyze_and_save, get_report, list_reports, recent_reports, delete_report.
• Crawl — crawl_site, list_crawls, get_crawl, get_crawl_page, delete_crawl.
• Trends — url_trends, compare_reports.
• Projects — list_projects, create_project, update_project, delete_project.
• Monitors — tick_monitors, run_monitor_now, list_monitors, create_monitor, toggle_monitor, delete_monitor, list_alerts, unread_alerts, mark_alerts_read.
• AI — run_fix, respond_write.
• Settings & license — get_settings, save_settings, license_status, activate_license.
• Export — open_report.

After changing any #[command] signature or a specta type, re-run rata codegen before touching the frontend.

¶Events (Rust → frontend)

Pushed over channels the frontend subscribes to:

• crawl — crawl progress (status / per-page / done).
• ai:fix — AI agent activity (status / tool / write).
• ai:confirm — pending write-confirmation requests.

¶Database (SQLite)

Secrets are not in the database — see Security.