feat(integrations): add create integration review request API and UI

Add a new Tauri command and front-end flow to create PRs/MRs.
The backend builds and validates provider-specific payloads and
endpoints, sends creation requests, and parses responses into the
app's review model. A Svelte dialog and a JS wrapper wire the UI to the
command so users can create requests from the Review Center.

- Implement provider payload and endpoint logic with unit tests
- Expose create_integration_review_request as a Tauri command
- Add CreateReviewDialog UI and integrate a creation button in Review Center

src-tauri/src/integrations.rs

@@ -5,11 +5,14 @@ use serde::{Deserialize, Serialize};
 use std::collections::BTreeSet;
 use std::time::Duration;
 
+mod creation;
+pub use creation::create_integration_review_request;
+
 const PAGE_SIZE: usize = 100;
 const REVIEW_REQUEST_TIMEOUT: Duration = Duration::from_secs(35);
 const AZURE_PROJECT_WORKERS: usize = 8;
 
-#[derive(Debug, Clone, PartialEq, Eq, Serialize)]
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 #[serde(rename_all = "camelCase")]
 pub struct IntegrationRepository {
     pub id: String,