fix(ci view): prevent crash when viewing unrun downstream pipeline triggers
Fixes a nil pointer dereference crash when pressing Enter on a bridge job (downstream pipeline trigger) that hasn't been triggered yet.
When a bridge job has status 'manual', 'created', 'pending', or 'skipped', the DownstreamPipeline field is nil. Previously, the code attempted to dereference this field without checking, causing a panic.
Now we check if DownstreamPipeline is nil before dereferencing. If nil, we display an informational modal with status-aware messaging explaining why the child pipeline isn't available yet. Users can dismiss the modal and continue using the application normally.
The fix includes:
- Nil check before accessing DownstreamPipeline
- Status-aware modal messages using user-friendly terminology
- Unit tests covering the crash scenario
Closes #7372 (closed)