fix(bootstrap): surface precise branch-not-found error to the developer

Replace the generic cliux.error+rethrow pattern with a single clean
Error throw so oclif prints one message. Message names both the repo
and the missing cli-use branch so the developer knows exactly what to
check on GitHub.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: cs-raj

.talismanrc

@@ -4,7 +4,7 @@ fileignoreconfig:
 - filename: packages/contentstack-audit/test/unit/mock/am-contents/environments/environments.json
   checksum: ffaaee9269a6e833cd3dbe337ddc5c060cce948519873c7a2777754519a31b52
 - filename: pnpm-lock.yaml
-  checksum: 649aae748e3ae8c157439dc6c7c9ea402cc19b4dab7ca64b7e4d839d1375df53
+  checksum: fda8964d238e0d30577ce8f5bf879a2102c69a7f9e83067ab1627b9b1db9d066
 - filename: packages/contentstack-audit/src/types/content-types.ts
   checksum: d16a65415c3184f15a807d58e5858310aeb5633794fc9075e36f89c94da636c3
 - filename: packages/contentstack-audit/src/audit-base-command.ts

packages/contentstack-bootstrap/messages/index.json

@@ -4,6 +4,7 @@
   "CLI_BOOTSTRAP_GITHUB_ACCESS_NOT_FOUND": "No Github access token found",
   "CLI_BOOTSTRAP_START_CLONE_APP": "Cloning the selected app",
   "CLI_BOOTSTRAP_REPO_NOT_FOUND": "Unable to find a repo for \"%s\"",
+  "CLI_BOOTSTRAP_APP_UNAVAILABLE": "Unable to download \"%s\": branch \"cli-use\" not found. Ensure the branch exists on the GitHub repository.",
   "CLI_BOOTSTRAP_NO_API_KEY_FOUND": "No API key generated for the stack",
   "CLI_BOOTSTRAP_STACK_CREATION_FAILED": "Unable to create stack for content \"%s\"",
   "CLI_BOOTSTRAP_APP_SELECTION_ENQUIRY": "Select an App",

packages/contentstack-bootstrap/src/bootstrap/index.ts

@@ -74,10 +74,8 @@ export default class Bootstrap {
       cliux.loader();
     } catch (error) {
       cliux.loader();
-      if (error instanceof GithubError) {
-        if (error.status === 404) {
-          cliux.error(messageHandler.parse('CLI_BOOTSTRAP_REPO_NOT_FOUND', this.appConfig.source));
-        }
+      if (error instanceof GithubError && error.status === 404) {
+        throw new Error(messageHandler.parse('CLI_BOOTSTRAP_APP_UNAVAILABLE', this.appConfig.source));
       }
       throw error;
     }