fix(webhook): sync repo default branch from webhook payloads

packages/das/src/webhook/handlers/issue.handler.ts

@@ -50,8 +50,14 @@ export class IssueHandler {
 
     await this.issueRepo.upsert(data, ["repoFullName", "issueNumber"]);
 
-    await this.repoRepo.update(repoFullName, {
+    const repoUpdate: Partial<Repo> = {
       lastEventAt: new Date().toISOString(),
-    });
+    };
+    const defaultBranch: string | null =
+      payload.repository?.default_branch ?? null;
+    if (defaultBranch) {
+      repoUpdate.defaultBranch = defaultBranch;
+    }
+    await this.repoRepo.update(repoFullName, repoUpdate);
   }
 }

packages/das/src/webhook/handlers/pull-request.handler.ts

@@ -53,9 +53,15 @@ export class PullRequestHandler {
 
     await this.prRepo.upsert(data, ["repoFullName", "prNumber"]);
 
-    await this.repoRepo.update(repoFullName, {
+    const repoUpdate: Partial<Repo> = {
       lastEventAt: new Date().toISOString(),
-    });
+    };
+    const defaultBranch: string | null =
+      payload.repository?.default_branch ?? null;
+    if (defaultBranch) {
+      repoUpdate.defaultBranch = defaultBranch;
+    }
+    await this.repoRepo.update(repoFullName, repoUpdate);
 
     // Enqueue metadata fetch (closing issues + body + lastEditedAt) on relevant actions.
     // Also run on `edited` so post-merge body edits are captured.

packages/das/src/webhook/webhook.service.ts

@@ -91,6 +91,9 @@ export class WebhookService {
     }
 
     switch (event) {
+      case "repository":
+        await this.handleRepositoryEvent(payload);
+        break;
       case "pull_request":
         await this.pullRequestHandler.handle(payload);
         if (payload.action === "labeled" || payload.action === "unlabeled") {
@@ -119,4 +122,22 @@ export class WebhookService {
         this.logger.debug(`Unhandled event type: ${event}`);
     }
   }
+
+  private async handleRepositoryEvent(
+    payload: Record<string, any>,
+  ): Promise<void> {
+    const repoFullName: string | undefined = payload.repository?.full_name;
+    if (!repoFullName) return;
+
+    const repoUpdate: Partial<Repo> = {
+      lastEventAt: new Date().toISOString(),
+    };
+    const defaultBranch: string | null =
+      payload.repository?.default_branch ?? null;
+    if (defaultBranch) {
+      repoUpdate.defaultBranch = defaultBranch;
+    }
+
+    await this.repoRepo.update(repoFullName, repoUpdate);
+  }
 }