fix(github): apply guest token to images in markdown sync (#10659)

* fix(github): apply guest token to images in markdown sync (#10516)

The appendGuestLinkToImage function existed but was never called from
getMarkdown(). Add it as the default preprocessor so image URLs include
a guest JWT token, allowing them to render on GitHub.

Signed-off-by: Daniel Kendall <dkendall@ledoweb.com>

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Signed-off-by: Don Kendall <kendall@donkendall.com>

* fix: formatting (prettier/eslint)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Signed-off-by: Don Kendall <kendall@donkendall.com>

---------

Signed-off-by: Don Kendall <kendall@donkendall.com>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

services/github/pod-github/src/sync/issues.ts

@@ -523,9 +523,7 @@ export class IssueSyncManager extends IssueSyncManagerBase implements DocSyncMan
               info.repository as Ref<GithubIntegrationRepository>,
               container.project,
               taskTypes[0]._id,
-              repo as GithubIntegrationRepository & {
-                repository: IntegrationRepositoryData
-              },
+              repo,
               !markdownCompatible
             )
           },