The left sidebar tracked when it first *observed* a running stage
(Date.now() on mount) instead of the stage's actual startedAt, so the
duration reset to 0s on every page load.
Compute elapsed time directly from stage.startedAt via a shared
elapsedSecsSince helper, dropping the runningStartRef tracking. The
stage meta bar already did this correctly but with a duplicated parser;
fold it onto the same helper.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
### Summary
Billing and stage lists now use the event-sourced `RunProjection` as
their source of truth, so running and retrying stages appear immediately
and runtimes keep advancing in the UI. This removes the checkpoint
completed-node bypass that hid in-flight work and froze totals until the
next server response.
### Plan Summary
- Store stage `started_at`, terminal `duration_ms`, server-internal
`usage`, and lifecycle `state` on `StageProjection`.
- Populate those fields from stage lifecycle events, including retry
transitions and per-attempt reset on new starts.
- Render `/runs/{id}/stages` and `/runs/{id}/billing` from
`RunProjection.iter_stages()`.
- Expose the new API/client fields and tick in-flight billing runtimes
on the web UI.
```mermaid
flowchart TB
Events["Stage lifecycle events"] --> Projection["RunProjection StageProjection"]
Projection --> StagesAPI["GET /runs/{id}/stages"]
Projection --> BillingAPI["GET /runs/{id}/billing"]
StagesAPI --> StageUI["Stage sidebar/stages view"]
BillingAPI --> BillingUI["Billing tab live totals"]
```
### Key decisions
Retry and revisit handling stays one row per node id: latest visit data
wins, while first-seen event sequence keeps ordering stable with
finalize output. `state` is stored rather than derived so `Retrying` is
representable, and old serialized projections still work through the
`effective_state()` fallback. Billing `usage` remains server-internal
and is skipped on the wire; public schemas only expose the fields needed
by `/stages`, `/billing`, and the frontend live timer.
Added focused reducer, server retry/revisit, API round-trip, billing UI,
and event invalidation coverage.
⚒️ Generated with [Fabro](https://fabro.sh)
---------
Co-authored-by: Fabro <noreply@fabro.sh>
Co-authored-by: Bryan Helmkamp <bryan@brynary.com>
These endpoints had zero CLI callers and served only the web UI demo.
Verification and retros were `not_implemented` stubs in real mode;
sessions had an in-memory implementation but no CLI usage. Removing
them shrinks the API surface and eliminates ~9,000 lines of dead code.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
