App desktop (Tauri), GitHub Actions de CI/release, elevação automática

- Move a UI de crates/sabia-cli/src/web/ para apps/gui/ui/: fonte única
  servida tanto pelo `sabia ui` quanto pelo app desktop.
- sabia-core::engine::Engine centraliza sessões de scan/monitor/update —
  usado pelo servidor local da CLI e pelo app Tauri, sem duplicar lógica.
- apps/gui/src-tauri: app desktop Tauri 2, mesma interface, comandos IPC
  espelhando a API HTTP. Pede elevação de administrador/root
  automaticamente ao abrir (modo monitor e captura crua exigem):
  manifesto requireAdministrator no Windows (UAC antes mesmo do app
  abrir), pkexec no Linux e osascript no macOS, com reinício automático
  e aviso + botão de nova tentativa na interface se for negada.
- Ícone gerado a partir do logo (apps/gui/src-tauri/icons/source.png).
- .github/workflows/ci.yml: fmt, clippy, testes (Linux/Windows/macOS),
  auditoria de dependências, compilação do app desktop.
- .github/workflows/release.yml: ao empurrar uma tag vX.Y.Z, builda a
  CLI (Linux x86_64/aarch64, macOS x86_64/aarch64, Windows x86_64) e o
  app desktop pras mesmas plataformas, publica tudo numa release do
  GitHub com checksums SHA-256.
- sabia-core::update: corrige o nome do asset esperado (casava pelo
  nome fixo, mas o release empacota com a versão no nome) e a extração
  (tar.gz no Linux/macOS, zip no Windows).
- LICENSE-MIT, LICENSE-APACHE, CHANGELOG.md com a entrada 0.1.0.
- cargo fmt + clippy (-D warnings) limpos em todo o workspace.

LICENSE-MIT

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 Sabiá contributors
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.