Refactor: remove desktop/Tauri bundle, add i18n, CI/CD pipeline

- Remove desktop (Tauri) bundle: docs/desktop.md, icons/, tauri.conf.json,
  src/desktop/mod.rs, gen/schemas/
- Remove build.rs (no longer needed)
- Add i18n system (crates/core-api, plugin-mobile-connector, web)
- Refactor config system (src/config.rs, boot_format.rs)
- Add mobile connector features (app, router, device pairing)
- Plugin system improvements (skald-core)
- Update dependencies (Cargo.lock, Cargo.toml)
- CI/CD: Gitea Actions workflows (nightly + release), package.sh,
  verify-version.sh, builds.skaldagent.net config

crates/skald-core/src/lib.rs

@@ -1,7 +1,7 @@
 //! The headless Skald core: storage, identity, LLM stack, tools, sessions.
 //!
-//! Nothing here knows what runs it. The process shell — HTTP server, desktop
-//! webview, setup wizard — lives in the crates that depend on this one. Concrete
+//! Nothing here knows what runs it. The process shell — HTTP server, setup
+//! wizard — lives in the crates that depend on this one. Concrete
 //! plugins are never named: `plugin::PluginManager` only ever sees
 //! `Arc<dyn Plugin>`, constructed by the consumer and handed to `Skald::new`.