The Execution tab's PipelinePhaseGroup was using sortByPriorityAndQueueTime
which ignores task dependencies entirely. Tasks now sort topologically via
topologicalSortPhases, matching the Plan tab's TaskGraph behavior.
- Add listInitiativeTaskDependencies tRPC procedure (bulk fetch)
- Fetch task deps in PipelineTab, group by phase, pass through
- Replace priority sort with topological sort in PipelinePhaseGroup
- Show "blocked by N" count on PipelineTaskCard