Plan 13 — Activity tab + Replay UI

[carlomigueldy]

Plan file: docs/superpowers/plans/2026-05-23-plan-13-activity-and-replay.md
Tag at close: v0.0.13-plan-13
Depends on: Plans 07 + 12

Goal

Surface the event log — the 'externalized truth' of spec §6.7 — as a live Activity tab plus a per-task Replay scrubber. Users can stream timestamped events and step backward/forward through a specific task's history.

Deliverable

• features/activity/ feature module.
• Virtualized live event stream (TanStack Virtual) with filter chips.
• <ReplayPane> with slider that scrubs through events; UI re-renders task state at each point.
• URL state for filters (deep-linkable).
• 60fps performance budget proven by perf test.
• F83–F88.

Out of scope (deferred to later plans)

• Cross-task replay → out of scope for v1
• Export-to-bug-report → out of scope until v1.1
• Settings → Plan 14

Workflow

• Branch from main via superpowers:using-git-worktrees: feat/plan-13-activity-and-replay.
• One PR closes this issue — include Closes #<this issue's number> in the PR description.
• Update docs/superpowers/plans/README.md to move this plan from "not started" to "shipped" in the same PR.
• Final step is the close-out commit and git tag v0.0.13-plan-13.
• All 5 quality gates apply (CONTRIBUTING.md).