feat(integrations): add Git hosting providers and Clone UI

Add integrations for GitHub, GitLab (cloud & self-hosted), Azure DevOps,
and Gitea, storing personal access tokens in the operating system
keychain. Azure DevOps supports multiple independently configurable
organizations, and the Clone → Integrations tab loads, filters, sorts,
and clones repositories using stored credentials. Update the API
contract, help overlay, README, changelog, and application version
metadata to document and ship the feature.

- Add list_integration_repositories API command and related types
- New Clone → Integrations UI with search, refresh, and direct clone
- Store tokens in OS keychain and support multiple Azure DevOps orgs

CHANGELOG.md

@@ -4,6 +4,53 @@ All notable user-facing changes to Gitty are documented in this file.
 
 The project uses calendar-style versions in the form `YYYY.M.PATCH`.
 
+## [2026.8.8] - 2026-08-29
+
+### Added
+
+- Git hosting integrations for GitHub, GitLab.com, GitLab Self-Managed,
+  Azure DevOps, and Gitea. Personal access tokens are stored separately in
+  the operating system keychain.
+- Azure DevOps supports multiple independently configurable organizations,
+  each with its own display name, organization URL, username, and token.
+- The Clone dialog has an Integrations tab that loads all repositories
+  available to the selected account, supports filtering and refresh, sorts
+  repositories alphabetically, and clones the selected repository directly
+  with its stored credentials.
+
+### Changed
+
+- Repository tabs use a more compact Git-client-style bar. Close buttons
+  remain visible and turn red only while hovered.
+- The integration repository list uses a narrow custom scrollbar that grows
+  only slightly on hover and no longer covers repository names or metadata.
+- Repository loading and status overlays use theme-aware design tokens with
+  improved contrast and a more compact presentation.
+
+### Fixed
+
+- Clearing sync settings on a branch that never had an upstream is now a safe
+  no-op instead of failing with a fatal Git error.
+
+## [2026.8.7] - 2026-08-23
+
+### Added
+
+- Appearance settings now offer Modern, Classic, and Custom styles. Custom
+  themes can define their own persisted color palette, while a complete light
+  theme is available alongside the refreshed dark appearance.
+- The branch visibility dialog groups local and remote branches into
+  collapsible sections with selected-branch counts. Local branches open by
+  default, while the remote group starts collapsed for quicker navigation.
+
+### Changed
+
+- Dark-theme colors, surfaces, controls, and focus outlines have been refined
+  for clearer interactive boundaries and more consistent contrast throughout
+  the application.
+- The branch visibility dialog follows the responsive layout and visual
+  language of the rest of Gitty more closely.
+
 ## [2026.8.6] - 2026-08-18
 
 ### Changed
@@ -243,6 +290,8 @@ The project uses calendar-style versions in the form `YYYY.M.PATCH`.
 [2026.07.22]: https://git.cbsk-tech.de/Christoph/GitLite/releases/tag/2026.7.22
 [2026.07.21]: https://git.cbsk-tech.de/Christoph/GitLite/releases/tag/2026.7.21
 [2026.7.20]: https://git.cbsk-tech.de/Christoph/GitLite/releases/tag/2026.7.20
+[2026.8.8]: https://git.cbsk-tech.de/Christoph/GitLite/releases/tag/2026.8.8
+[2026.8.7]: https://git.cbsk-tech.de/Christoph/GitLite/releases/tag/2026.8.7
 [2026.8.6]: https://git.cbsk-tech.de/Christoph/GitLite/releases/tag/2026.8.6
 [2026.8.5]: https://git.cbsk-tech.de/Christoph/GitLite/releases/tag/2026.8.5
 [2026.8.4]: https://git.cbsk-tech.de/Christoph/GitLite/releases/tag/2026.8.4