Add terminal client, memory, model fallback, version and install improvements

- codecraft: full-screen terminal client (ratatui) – local tools and files,
  models via the CodeCraft server gateway or own providers (standalone with a
  guided setup), slash commands, @files, permission dialogs, resume, update
- Static Linux CLI builds (x86_64/aarch64, cargo-zigbuild) served by the
  server: /cli/install.sh and /cli/download/<target>
- Project memory (remember tool, .codecraft/memory.md) and personal memory
- Model fallback when a host is unreachable or a budget is used up
- Version/commit in UI and health, daily release check, "What's new" dialog
- PWA: install button, maskable icon, manifest id and screenshots
- Case-insensitive detection of connection errors for retries

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

server/src/auth.rs

@@ -253,7 +253,9 @@ pub async fn info(State(app): State<Arc<App>>, headers: HeaderMap) -> Json<Value
     let user = current_user(&app, &headers);
     Json(json!({
         "name": "CodeCraft",
-        "version": env!("CARGO_PKG_VERSION"),
+        "version": crate::update::VERSION,
+        "commit": crate::update::commit(),
+        "update": if user.as_ref().is_some_and(|u| u.is_admin()) { app.update.latest.lock().unwrap().clone() } else { None },
         "setup_required": app.setup_code.lock().unwrap().is_some(),
         "oidc": if cfg.auth.oidc.enabled { json!({"label": cfg.auth.oidc.button_label}) } else { Value::Null },
         "user": user,