aisman

Direct session 57, Step 2: Step 4 multi-task redesign + output file completion:
- Step 4: Remove separate content poll timer — route through existing project tab poller
- Step 4: Multi-task architecture with S.workflow.s4Tasks[] array state
- Step 4: Vertical tab sidebar — one tab per workflow loop named after file, with status icons
- Step 4: Rewrite notifyWorkflowIfWaiting() for multi-task task array
- Step 4: HTML restructure — empty state + tasks layout with sidebar and task panel
- SCSS: Tab sidebar styles for Step 4 multi-task layout
- Step 4: renderS4TaskContent(task) — state-based full re-render replacing multiple show/hide helpers
- Step 4: processS4Task(task) stores sessionId/issueIds at creation, switches to original session on success
- Step 4: Remove stopS4ContentPoll() call from gotoWfStep()