Restored the `REPO_OVERRIDE_RE` regex export from core and aligned the dashboard's `githubTracking` component to consume it, fixing the export contract that was broken in FN-3921. Added tests in both core and dashboard packages to cover the regex behavior.
Fusion-Task-Id: FN-3921
Exported the repo override regex from `@fusion/core` for use across packages, replacing an internal import in the dashboard's GitHub tracking component with the public API from core. Tests were updated in both packages to cover the new export.
Fusion-Task-Id: FN-3920
Restores a local GitHub tracking regex helper in the dashboard and adds regression tests to prevent future regressions. The feature restores functionality that was previously removed, with tests covering the helper's behavior.
Fusion-Task-Id: FN-3918
