Release 0.0.6: token-gated updates (M13) with encrypted storage

- updates gated to Gitea account holders via a Personal Access Token (D18
  revised: anonymous HTTP -> authenticated HTTP, since the instance requires
  sign-in for all anonymous access)
- token stored encrypted in the OS keyring (secret-tool) when available, with
  a 0600-file fallback; $RIGDOCTOR_TOKEN override; auto-migrate file->keyring
  once libsecret-tools is installed
- core/updates: token-aware fetch_latest + update_state (no-token/auth/network/
  up-to-date/available)
- CLI: rigdoctor login / logout / update [--check]
- GUI: Setup "Update access" panel (token field, get-a-token, backend status);
  sidebar update states; libsecret-tools added to the installer catalog
- token storage tests (file fallback + env override, keyring mocked)
- version 0.0.6, CHANGELOG, docs

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

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "rigdoctor"
-version = "0.0.5"
+version = "0.0.6"
 description = "Modular hardware monitoring & crash diagnostics for Linux gamers."
 readme = "README.md"
 requires-python = ">=3.11"