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

package.json

@@ -1,6 +1,6 @@
 {
   "name": "gitty",
-  "version": "2026.8.7",
+  "version": "2026.8.8",
   "private": true,
   "type": "module",
   "scripts": {