feat(timeline): agent activity timeline panel for a task

[bborn]

Summary

Gives a task a compact, chronological activity timeline of its lifecycle, built from the event_log and updating live via the existing SSE feed. Borrows the "agent state timeline" idea from herdr-insight.

A task now shows an accurate, ordered event timeline with real timestamps — state transitions (queued → processing → blocked → done), retries, blocks, and completion — that updates live as new events land.

Changes

internal/db

• New GetTaskTimeline(taskID, limit) builds chronological (oldest-first) TaskTimelineEntry values from event_log, mapping each row to a short label (Created, Completed, Blocked, Retried, and queued → processing style transitions).
• Status changes now persist their {old,new} values in the event_log metadata column (recordEventMeta / marshalEventMetadata), so transition labels are accurate.
• RetryTask records a distinct task.retry event so retries are visible on the timeline.

internal/ui (TUI detail view)

• New Activity Timeline section in the detail view, each entry showing a real timestamp, an icon, and a short label.
• Reloaded on the periodic Refresh() tick and folded into the render cache key, so it updates live as events land (no manual reopen).

internal/web

• GET /api/tasks/{id}/timeline returns the timeline as JSON with real UTC timestamps.
• The existing per-task SSE stream now also emits timeline events as new lifecycle events occur, so the web detail page can update live.

Tests

• internal/db: timeline builder (chronological order, transitions, retry, limit, empty) + label mapping table.
• internal/web: timeline endpoint (shape, RFC3339 timestamps, transition label) + invalid-id.
• internal/ui: timeline renders in detail content and updates live after a new event on Refresh().

go build ./..., go test for the three touched packages, and golangci-lint run (v2.8.0) all pass.

Follow-ups

• The web SPA (internal/web/ui/dist, built out-of-repo behind the ui build tag) needs a small frontend change to render the new endpoint/SSE timeline events; the backend API + stream are ready for it.

🤖 Generated with Claude Code

[bborn]

✅ QA: Agent activity timeline

Drove the real ty TUI + web API against an isolated throwaway instance (scripts/qa), seeding a task through a full lifecycle: backlog → queued → processing → blocked → retry → processing → done.

TUI detail view — Activity Timeline

Renders chronologically with real timestamps, status-aware icons, and the retry feedback. The redundant bare Blocked/Completed lifecycle rows are suppressed so each block/finish appears once.

Web API — GET /api/tasks/{id}/timeline

Returns the same chronological timeline as JSON with real UTC (RFC3339) timestamps:

[
  {"id":1,"event_type":"task.created","label":"Created","detail":"Add Stripe billing webhooks","created_at":"2026-06-23T22:40:52Z"},
  {"id":2,"event_type":"task.updated","label":"backlog → queued","created_at":"2026-06-23T22:40:52Z"},
  {"id":3,"event_type":"task.updated","label":"queued → processing","created_at":"2026-06-23T22:40:54Z"},
  {"id":4,"event_type":"task.updated","label":"processing → blocked","created_at":"2026-06-23T22:40:55Z"},
  {"id":6,"event_type":"task.retry","label":"Retried","detail":"Verify signature with the new secret","created_at":"2026-06-23T22:40:56Z"},
  {"id":7,"event_type":"task.updated","label":"blocked → queued","created_at":"2026-06-23T22:40:56Z"},
  {"id":8,"event_type":"task.updated","label":"queued → processing","created_at":"2026-06-23T22:40:57Z"},
  {"id":9,"event_type":"task.updated","label":"processing → done","created_at":"2026-06-23T22:40:58Z"}
]

(Raw event_log had 10 rows; the redundant task.blocked id=5 and task.completed id=10 are correctly suppressed.)

Web SSE — live updates

With the per-task stream (GET /api/tasks/{id}/stream) open, transitioning the task pushed timeline events in real time:

event: timeline
data: {"id":13,"event_type":"task.updated","label":"queued → processing","created_at":"2026-06-23T22:43:08Z"}
event: timeline
data: {"id":14,"event_type":"task.updated","label":"processing → blocked","created_at":"2026-06-23T22:43:09Z"}

Acceptance criteria

• Accurate, chronological event timeline with real timestamps
• State transitions (queued→processing→blocked→done), retries, blocks, completion
• Updates live as new events land (TUI Refresh() tick + web SSE timeline events)
• Tests: internal/db, internal/web, internal/ui — all green; golangci-lint v2.8.0 clean

Note

• QA surfaced duplicate blocked/done rows; fixed in 3ecec1f9 (dedupe + status-aware icons). The web SPA frontend (out-of-repo, ui build tag) still needs a small change to render the new endpoint/SSE events — backend is ready.

_{QA via isolated ty instance; live daemon/DB untouched.}