Rework Tasks tab: Chains section, checklist modal, project visibility

The flat Tasks-tab atom list was silently dumping every chain step
(locked and unlocked) and dormant bucket-pool items in as ordinary
undated cards, with no chain/project context and no protection against
completing a locked step out of order.

- CompleteNativeTask now rejects completing a locked chain task
  (ErrChainTaskLocked), mapped to 400 in both the widget and web
  complete-atom handlers.
- Chain tasks and dormant bucket items are excluded from the flat atom
  list; a new "Chains" section shows one card per active/paused chain
  with the current step and N/M progress.
- New chain checklist modal (GET /chains/{id}) lists every position in
  order with pause/resume/abandon -- the web view originally deferred
  as Android-only.
- Fixed a real bug this surfaced: resuming a paused chain only flipped
  the status flag, never unlocking the deferred successor, so a chain
  paused right after a completion stayed stuck forever. SetChainStatus
  now catches up the deferred advancement on resume, idempotently.
- Atom cards gained a project-name chip for general visibility.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EZ7ikw2ukGJFTHE3bJS7zL

1 files changed, 1 insertions, 1 deletions

diff --git a/docs/superpowers/specs/2026-07-15-linear-task-chains-design.md b/docs/superpowers/specs/2026-07-15-linear-task-chains-design.md
index 16e5337..13d9077 100644
--- a/docs/superpowers/specs/2026-07-15-linear-task-chains-design.md
+++ b/docs/superpowers/specs/2026-07-15-linear-task-chains-design.md
@@ -1,6 +1,6 @@
 # Linear Task Chains with WIP Limits — Design
 
-**Status:** Implemented 2026-07-17. Backend (migration 026, store, HTTP API), web timeline position badge, and Android widget data layer + row badge all shipped with tests (`go test ./...` green). See `docs/superpowers/plans/2026-07-17-linear-task-chains.md` for the task breakdown. Not built: a dedicated Android checklist screen for browsing a full chain (locked + unlocked) -- the row-level badge and `GET /api/widget/chains/{id}` endpoint exist, but the standalone browsable view described in "Visibility" below is deferred, consistent with this spec's own "Web UI specifics for the chain/checklist view" being out of scope.
+**Status:** Implemented 2026-07-17-18. Backend (migration 026, store, HTTP API), web timeline position badge, Android widget data layer + row badge, and (2026-07-18, extending beyond this spec's original web-out-of-scope note, per user request) a full web checklist view -- a "Chains" section on the Tasks tab plus a modal listing every position in order with pause/resume/abandon -- all shipped with tests (`go test ./...` green). See `docs/superpowers/plans/2026-07-17-linear-task-chains.md` for the task breakdown. Still not built: the equivalent dedicated Android checklist screen (row badge and `GET /api/widget/chains/{id}` exist; no standalone Android view yet).
 
 ## Context