docs: spec + plan for phase 3b.1 manual session entry/edit + admin stop/fix

2026-06-17 22:25:28 +02:00
parent 70ac27ec8e
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--- a/docs/superpowers/plans/2026-06-17-phase-3b1-manual-sessions.md
+++ b/docs/superpowers/plans/2026-06-17-phase-3b1-manual-sessions.md
@@ -0,0 +1,295 @@
+# Phase 3b·1 — Manual Session Entry/Edit + Admin Stop/Fix — Implementation Plan
+
+> **For agentic workers:** Implement task-by-task with TDD. Steps use checkbox (`- [ ]`).
+> Spec: `docs/superpowers/specs/2026-06-17-phase-3b1-manual-sessions-design.md`.
+
+**Goal:** Admin can list/filter all sessions, manually create a completed session for a worker,
+edit any session (server recomputes duration), and stop/cancel a worker's active session — and the
+worker's stopwatch converges to admin changes within ~15s (no stuck state).
+
+**Architecture:** New admin-gated write endpoints + a users-roster endpoint in `routes/admin.ts`;
+a new admin **Sessies** screen + shared create/edit form; Stop/Annuleer actions on Live; worker
+polls + reconciles. **No DB migration** (reuses existing `work_sessions` columns).
+
+**Tech Stack:** Hono + Drizzle + libsql (api), Vite+React+react-query (admin, worker),
+`@solelog/shared` zod, vitest. Yarn 4 monorepo.
+
+## Global Constraints
+
+- **TDD**: failing test → see it fail → minimal implementation → green → commit.
+- **Commit per task**, conventional-commit message; commit **locally only** (no push/remote/amend);
+  stage only your task's files.
+- **oxlint + oxfmt on changed files only.** `.oxfmtrc.json` now uses `trailingComma: "all"`
+  (prettier-style) — keep trailing commas on multiline params/args/arrays/objects; `docs/**` and
+  `**/drizzle/**` are ignored by the formatter. 2-space, single quotes, semicolons, width 100.
+- **Dutch UI strings.**
+- **No DB migration** this cycle. **Do not start the API server** (tests use in-process
+  `app.request`); if you must, kill the tree + free port 3000 afterward (Windows lock trap).
+- Reuse `toWorkSession` (`apps/api/src/lib/work-session.ts`) for session responses. New admin
+  routes live in `apps/api/src/routes/admin.ts`, already behind the `/api/admin/*` admin guard.
+
+## File Structure
+
+```
+packages/shared/src/index.ts            MODIFY  CreateManualSessionInput, AdminUpdateSessionInput
+apps/api/src/routes/admin.ts            MODIFY  GET /api/admin/users; POST/PUT/stop/discard sessions
+apps/api/test/admin.test.ts             MODIFY
+apps/admin/src/api/admin-sessions.ts    MODIFY  add list/users/create/update/stop/discard hooks
+apps/admin/src/screens/Sessions.tsx     CREATE  list + status filter + row actions
+apps/admin/src/components/SessionForm.tsx CREATE create/edit form
+apps/admin/src/components/Sidebar.tsx    MODIFY  add 'Sessies' nav; drop 'Handmatig' from soon
+apps/admin/src/App.tsx                   MODIFY  add /sessies route
+apps/admin/src/screens/Live.tsx          MODIFY  Stop/Annuleer on LiveCard
+apps/admin/src/styles.css                MODIFY  table/form/action styles
+apps/admin/src/screens/Sessions.test.tsx, components/SessionForm.test.tsx, screens/Live.test.tsx  TEST
+apps/worker/src/api/sessions.ts          MODIFY  refetchInterval 15000
+apps/worker/src/screens/Stopwatch.tsx    MODIFY  reconcile + 409 handling
+apps/worker/src/screens/Stopwatch.test.tsx TEST
+```
+
+---
+
+### Task 1: Shared contracts
+
+**Files:** `packages/shared/src/index.ts`; test `packages/shared` (or assert via api tests — add a
+tiny parse test if shared has a test setup, else cover via Task 2's api tests).
+
+**Interfaces — Produces:**
+- `CreateManualSessionInput = z.object({ user_id: z.string(), activity_id: z.number().int(),
+  insole_type: InsoleType, pair_count: z.number().int().min(1), start_time: z.string(),
+  end_time: z.string(), paused_seconds: z.number().int().min(0).default(0),
+  notes: z.string().nullable().optional() })`.
+- `AdminUpdateSessionInput = z.object({ activity_id: z.number().int(), insole_type:
+  InsoleType.nullable(), pair_count: z.number().int().min(1), start_time: z.string(),
+  end_time: z.string().nullable(), paused_seconds: z.number().int().min(0),
+  notes: z.string().nullable(), status: SessionStatus })`.
+
+- [ ] **Step 1:** If `packages/shared` has no test runner, skip a standalone test here and rely on
+  Task 2's API tests to exercise the schemas (note this in the commit). Otherwise add a parse
+  test (valid input parses; `pair_count: 0` fails).
+- [ ] **Step 2:** Add both schemas + inferred types after `StartSessionInput`/`AdminUser`.
+- [ ] **Step 3:** `yarn workspace @solelog/api typecheck` (shared is consumed there) — green.
+- [ ] **Step 4: Commit** — `feat(shared): manual-session create/update contracts`.
+
+---
+
+### Task 2: Backend — admin session write endpoints + users roster
+
+**Files:** `apps/api/src/routes/admin.ts`; test `apps/api/test/admin.test.ts`.
+
+**Interfaces — Produces** `GET /api/admin/users`, `POST /api/admin/sessions`,
+`PUT /api/admin/sessions/:id`, `POST /api/admin/sessions/:id/stop`,
+`POST /api/admin/sessions/:id/discard`.
+
+- [ ] **Step 1: Failing tests** (helpers: `createTestUser`/`bearer`/`seedActivity`; create an admin
+  with `authToken(app, email, 'admin')` per the existing pattern):
+  - `GET /api/admin/users` (admin) returns objects with `id/name/email`; 403 for a worker.
+  - `POST /api/admin/sessions` (admin) with a worker's id + activity + `start_time`/`end_time` 1h
+    apart + `paused_seconds: 600` → 201/200 with `source==='manual'`, `status==='completed'`,
+    `duration_seconds === 3000` (3600−600).
+  - `POST` with `end < start` → 400; unknown `user_id`/`activity_id` → 404/400.
+  - `PUT /api/admin/sessions/:id` edits a session and recomputes duration; `end<start` → 400.
+  - `POST …/:id/stop` on another user's **active** session → completed with computed duration;
+    `…/:id/discard` → `status==='discarded'`. Worker token on any of these → 403.
+- [ ] **Step 2: Run — fail** (routes 404).
+- [ ] **Step 3: Implement** in `admin.ts` (imports: `and, eq, asc, desc` from drizzle-orm,
+  `CreateManualSessionInput`, `AdminUpdateSessionInput` from `@solelog/shared`, `activities`,
+  `user`, `workSessions` from schema, `toWorkSession`). All routes sit after the existing
+  `/api/admin/*` guard (already admin-gated).
+
+```ts
+adminRoutes.get('/api/admin/users', async (c) => {
+  const rows = await db
+    .select({ id: user.id, name: user.name, email: user.email })
+    .from(user)
+    .orderBy(asc(user.name));
+  return c.json(rows);
+});
+
+function computeDuration(startMs: number, endMs: number, paused: number) {
+  return Math.max(0, Math.round((endMs - startMs) / 1000) - paused);
+}
+
+adminRoutes.post('/api/admin/sessions', async (c) => {
+  const parsed = CreateManualSessionInput.safeParse(await c.req.json().catch(() => null));
+  if (!parsed.success) return c.json({ error: 'Invalid input' }, 400);
+  const d = parsed.data;
+  const start = new Date(d.start_time);
+  const end = new Date(d.end_time);
+  if (Number.isNaN(start.getTime()) || Number.isNaN(end.getTime()) || end < start)
+    return c.json({ error: 'Invalid input' }, 400);
+  const [u] = await db.select({ id: user.id }).from(user).where(eq(user.id, d.user_id));
+  if (!u) return c.json({ error: 'User not found' }, 404);
+  const [act] = await db.select().from(activities).where(eq(activities.id, d.activity_id));
+  if (!act) return c.json({ error: 'Activity not found' }, 404);
+  if (d.paused_seconds > Math.round((end.getTime() - start.getTime()) / 1000))
+    return c.json({ error: 'Invalid input' }, 400);
+  const [row] = await db
+    .insert(workSessions)
+    .values({
+      userId: d.user_id,
+      activityId: d.activity_id,
+      insoleType: d.insole_type,
+      pairCount: d.pair_count,
+      startTime: start,
+      endTime: end,
+      durationSeconds: computeDuration(start.getTime(), end.getTime(), d.paused_seconds),
+      pausedSeconds: d.paused_seconds,
+      pausedAt: null,
+      status: 'completed',
+      source: 'manual',
+      notes: d.notes ?? null,
+    })
+    .returning();
+  return c.json(toWorkSession(row, { activityName: act.name }));
+});
+```
+
+  - **PUT `:id`** — load the row (any user); 404 if missing; validate activity; if `end_time`
+    present validate `end ≥ start` and `paused ≤ span`, set `durationSeconds` via `computeDuration`,
+    else `durationSeconds = null` and (if `status==='active'`) keep it open. Set the editable
+    fields; return `toWorkSession`.
+  - **stop `:id`** — load active row; if `pausedAt`, fold the open span into `pausedSeconds`;
+    `end=now`; `durationSeconds=computeDuration(...)`; `status='completed'`, `pausedAt=null`.
+  - **discard `:id`** — load active row; `status='discarded'`, `end=now`.
+  - Register `stop`/`discard` (literal subpaths) and the bare `:id` PUT so they don't collide
+    (Hono matches `/api/admin/sessions/:id/stop` distinctly from `/:id`).
+- [ ] **Step 4: Run tests + typecheck — green.**
+- [ ] **Step 5: Commit** — `feat(api): admin manual-session create/edit/stop/discard + users roster`.
+
+---
+
+### Task 3: Admin — api hooks + Sessions screen (list + filter + nav/route)
+
+**Files:** `apps/admin/src/api/admin-sessions.ts`, `apps/admin/src/screens/Sessions.tsx` (create),
+`apps/admin/src/components/Sidebar.tsx`, `apps/admin/src/App.tsx`, `apps/admin/src/styles.css`;
+test `apps/admin/src/screens/Sessions.test.tsx`.
+
+**Interfaces — Produces** `useAllSessions`, `useAdminUsers`, `useCreateManualSession`,
+`useUpdateSession`, `useAdminStopSession`, `useAdminDiscardSession`.
+
+- [ ] **Step 1: Failing test** (mock `apiFetch`): `Sessions` renders a row per session (worker +
+  activity + worked); the status filter narrows the list (e.g. selecting "actief" shows only
+  active); `Stop`/`Annuleer` appear only on active rows and call the right endpoints; ✎ present on
+  all rows.
+- [ ] **Step 2: Run — fail.**
+- [ ] **Step 3: Hooks** in `api/admin-sessions.ts` (keep `useActiveSessions`):
+
+```ts
+export function useAllSessions() {
+  return useQuery({
+    queryKey: ['admin', 'sessions', 'all'],
+    queryFn: () => apiFetch<WorkSession[]>('/api/admin/sessions'),
+  });
+}
+export function useAdminUsers() {
+  return useQuery({
+    queryKey: ['admin', 'users'],
+    queryFn: () => apiFetch<{ id: string; name: string; email: string }[]>('/api/admin/users'),
+  });
+}
+// useCreateManualSession / useUpdateSession / useAdminStopSession / useAdminDiscardSession:
+// useMutation hitting POST /api/admin/sessions, PUT /api/admin/sessions/:id,
+// POST /api/admin/sessions/:id/stop|/discard; each onSuccess invalidates ['admin','sessions'].
+```
+
+- [ ] **Step 4: Sidebar + route** — add `{ to: '/sessies', label: 'Sessies' }` to `navItems` in
+  `Sidebar.tsx`; remove `'Handmatig'` from `soonItems` (leaves `['Rapporten', 'Gebruikers']`). In
+  `App.tsx` import `Sessions` and add `<Route path="/sessies" element={<Sessions />} />`.
+- [ ] **Step 5: Screen** — `Sessions.tsx`: title "Sessies", a status `<select>` filter
+  (alle/actief/voltooid/geannuleerd), `+ Nieuwe registratie` button (opens the form from Task 4 —
+  for now a stub/`onCreate` prop or local state placeholder), a table/list of rows with worked
+  time (reuse `formatTime` from `lib/elapsed`; show `Pauze …` when `paused_seconds>0`), ✎ edit and
+  (active only) `Stop`/`Annuleer` buttons wired to the hooks. Loading/error/empty states in Dutch.
+- [ ] **Step 6: Styles** — add `.sessions-*`/table/action-button CSS to `styles.css`.
+- [ ] **Step 7: Run admin tests + typecheck + build — green.**
+- [ ] **Step 8: Commit** — `feat(admin): sessions management screen (list + filter + actions)`.
+
+---
+
+### Task 4: Admin — create/edit session form
+
+**Files:** `apps/admin/src/components/SessionForm.tsx` (create), wire into
+`apps/admin/src/screens/Sessions.tsx`, `apps/admin/src/styles.css`; test
+`apps/admin/src/components/SessionForm.test.tsx`.
+
+- [ ] **Step 1: Failing tests** (mock `apiFetch`/hooks): in **create** mode the form shows a worker
+  picker (from `useAdminUsers`) and submitting posts `CreateManualSessionInput` with the entered
+  values; in **edit** mode it prefills from the session, hides the worker picker, and submitting
+  PUTs the changed fields. The "gewerkt" preview = `end − start − paused`.
+- [ ] **Step 2: Run — fail.**
+- [ ] **Step 3: Implement `SessionForm.tsx`** — props `{ mode: 'create' | 'edit', session?,
+  onClose }`. Fields: worker `<select>` (create only), activity `<select>` (from `useActivities`),
+  insole-type toggles, pair-count stepper, start/end `datetime-local`, paused (minutes or H:MM),
+  status `<select>` (edit only), notes `<textarea>`, and a derived "gewerkt" line. Build the ISO
+  `start_time`/`end_time` from the datetime-local values. Submit via `useCreateManualSession` /
+  `useUpdateSession`; close on success. Inline error on 400.
+- [ ] **Step 4: Wire into Sessions** — `+ Nieuwe registratie` opens it in create mode; ✎ opens it
+  in edit mode with the row's session. Modal or inline panel — keep it simple.
+- [ ] **Step 5: Run admin tests + typecheck + build — green.**
+- [ ] **Step 6: Commit** — `feat(admin): manual session create/edit form`.
+
+---
+
+### Task 5: Admin — Stop/Annuleer on the Live view
+
+**Files:** `apps/admin/src/screens/Live.tsx`, `apps/admin/src/styles.css`; test
+`apps/admin/src/screens/Live.test.tsx`.
+
+- [ ] **Step 1: Failing test:** an active LiveCard shows `Stop` and `Annuleer`; clicking `Stop`
+  calls `POST /api/admin/sessions/:id/stop`, `Annuleer` calls `…/discard`.
+- [ ] **Step 2: Run — fail.**
+- [ ] **Step 3: Implement** — add the two buttons to `LiveCard`, wired to `useAdminStopSession` /
+  `useAdminDiscardSession`; on success the active query invalidates and the card drops off.
+- [ ] **Step 4: Run admin tests + typecheck + build — green.**
+- [ ] **Step 5: Commit** — `feat(admin): stop/cancel an active session from the live view`.
+
+---
+
+### Task 6: Worker — poll + reconcile to server truth
+
+**Files:** `apps/worker/src/api/sessions.ts`, `apps/worker/src/screens/Stopwatch.tsx`; test
+`apps/worker/src/screens/Stopwatch.test.tsx`.
+
+- [ ] **Step 1: Failing tests** (mock `apiFetch`): with a session running locally, when the
+  active-sessions query resolves to a list **without** that session, the stopwatch resets to the
+  idle/start state and shows **"Deze sessie is door de beheerder gestopt."**; a 409 from the stop
+  mutation resets locally (no error surfaced).
+- [ ] **Step 2: Run — fail.**
+- [ ] **Step 3: Poll** — in `api/sessions.ts`, add `refetchInterval: 15000` to `useActiveSessions`.
+- [ ] **Step 4: Reconcile** — in `Stopwatch.tsx`, extend the active-session effect: when
+  `activeSessionsQuery.data` is present and the worker has a local `sessionId` that is **not** in
+  the returned active list, call `resetTimer()` and set a transient `stoppedByAdmin` notice
+  (cleared on next start). Keep the existing "adopt an active session when idle" recovery.
+- [ ] **Step 5: 409 handling** — give `useStopSession`/`useDiscardSession` (or the `handleStop`/
+  `handleDiscard` callers) an error path: if the error is `ApiError` with `status === 409`, call
+  `resetTimer()` (it's already closed) instead of leaving the timer stuck.
+- [ ] **Step 6: Run worker tests + typecheck + build — green.**
+- [ ] **Step 7: Commit** — `feat(worker): poll + reconcile stopwatch to server (admin stop/cancel)`.
+
+---
+
+### Task 7: Docs, lint, verification
+
+**Files:** `docs/roadmap.md`, `docs/sessions/2026-06-17-phase-3b1-manual-sessions.md` (create).
+
+- [ ] **Step 1: Lint/format** — `npx oxlint` clean; `npx oxfmt` on changed files only.
+- [ ] **Step 2: Full green** — `yarn workspace @solelog/api typecheck && test`;
+  `yarn workspace @solelog/admin typecheck && test && build`;
+  `yarn workspace @solelog/worker typecheck && test && build`.
+- [ ] **Step 3: Live smoke (preferred)** — start API, seed; as admin: `GET /api/admin/users`,
+  `POST /api/admin/sessions` (manual, confirm duration excludes paused + `source=manual`),
+  `PUT` edit, `stop`/`discard` on a worker's active session; then **kill the server tree + free
+  port 3000**.
+- [ ] **Step 4: Docs** — session log (goal/work/verification/outcome) + a roadmap note (Phase 3b·1
+  done; reports/export and user management remain).
+- [ ] **Step 5: Commit** — `docs: phase 3b·1 manual-sessions session log + roadmap note`.
+
+## Self-Review notes
+
+- Duration is always derived server-side (`computeDuration`) — never accepted from the client.
+- `stop`/`discard` literal subpaths vs the bare `:id` PUT don't collide in Hono.
+- Worker reconciliation keys off "my local session id is absent from the server's active list" —
+  covers admin stop, admin discard, and admin edit-to-completed alike.
+- No migration: all fields already exist on `work_sessions` (incl. pause fields from the prior
+  cycle).
--- a/docs/superpowers/specs/2026-06-17-phase-3b1-manual-sessions-design.md
+++ b/docs/superpowers/specs/2026-06-17-phase-3b1-manual-sessions-design.md
@@ -0,0 +1,112 @@
+# Phase 3b·1 — Manual Session Entry/Edit + Admin Stop/Fix — Design
+
+- **Created:** 2026-06-17
+- **Status:** Approved (brainstorming) — ready for implementation plan
+- **Tracker:** Plane (workspace `solelog`, project SoleLog)
+- **Cycle:** First of three Phase 3b cycles (then reports/export, then user management)
+- **Touches:** `packages/shared`, `apps/api`, `apps/admin`, `apps/worker`
+
+## Goal
+
+An admin can find any work session, **create** a manual one for a worker, **edit/correct** any
+session, and **stop or cancel** a worker's stuck active session — the "manual fallback wherever
+something fails" from the vision. Because the backend is the source of truth, the **worker
+converges** to admin changes (no stuck stopwatch).
+
+_Done when:_ an admin can list/filter all sessions, hand-create a completed session for a worker,
+edit any session's fields (server recomputes duration), and stop/cancel a worker's active
+session — and within ~15s the worker's stopwatch reflects a stop/cancel done by the admin.
+
+## Scope decisions (confirmed during brainstorming, 2026-06-17)
+
+1. **Slicing:** three sequenced 3b cycles; **this one first** (manual entry/edit + admin
+   stop/fix), then reports/export, then user management.
+2. **Sessions UI:** a full **"Sessies"** admin screen (the all-sessions list deferred from 3a
+   lands here; the reports cycle reuses it).
+3. **Editable fields:** start/end time, activity, insole type, pair count, paused seconds,
+   notes, status. The worker is chosen **only on create** — no reassignment on edit. Duration is
+   always **derived** server-side (`end − start − paused`), never typed.
+4. **Worker convergence:** folded into this cycle — the worker polls and reconciles to server
+   truth (an admin stop/cancel reflects on the phone within ~15s; no stuck state).
+
+## A. Backend (under the existing admin-gated `/api/admin/*` guard in `routes/admin.ts`)
+
+- `GET /api/admin/users` — `{ id, name, email }[]` from the `user` table (ordered by name), to
+  populate the create form's worker picker. Direct DB query — no better-auth client dependency.
+- `POST /api/admin/sessions` — manual create. Body `CreateManualSessionInput`:
+  `user_id, activity_id, insole_type, pair_count, start_time, end_time, paused_seconds?, notes?`.
+  Produces a **completed** session, `source='manual'`, `paused_at=null`,
+  `duration_seconds = max(0, round((end−start)/1000) − paused_seconds)`.
+- `PUT /api/admin/sessions/:id` — edit any session. Body `AdminUpdateSessionInput`:
+  `activity_id, insole_type, pair_count, start_time, end_time(nullable), paused_seconds, notes,
+  status`. Recomputes `duration_seconds` from times − paused when `end_time` is present; when
+  `status='active'`/`end_time` null, `duration_seconds=null`. No user reassignment.
+- `POST /api/admin/sessions/:id/stop` — quick "stop now": fold any open pause, `end=now`,
+  `status='completed'`, recompute duration.
+- `POST /api/admin/sessions/:id/discard` — `status='discarded'`, `end=now`.
+
+New `@solelog/shared` contracts: `CreateManualSessionInput`, `AdminUpdateSessionInput`. **No DB
+migration** — reuses existing `work_sessions` columns (incl. the pause fields). Responses use the
+existing `toWorkSession` mapper (so they carry `user_name`/`activity_name` where joined).
+
+### Validation
+`end ≥ start`; `pair_count ≥ 1`; `paused_seconds ≥ 0` and `≤ (end−start)`; activity must exist;
+user must exist (create); `insole_type` a valid `InsoleType`. Invalid → 400; missing
+session/user → 404. No hard delete — cancellation is `status='discarded'` (already excluded from
+exports).
+
+## B. Admin UI
+
+- **`components/Sidebar.tsx`** — add `{ to: '/sessies', label: 'Sessies' }` to `navItems`; drop
+  `'Handmatig'` from the muted `soonItems` (now built → leaves `['Rapporten', 'Gebruikers']`).
+- **`App.tsx`** — add `<Route path="/sessies" element={<Sessions />} />`.
+- **`screens/Sessions.tsx`** — lists all sessions via `useAllSessions` (`GET /api/admin/sessions`,
+  newest first), a status filter (alle / actief / voltooid / geannuleerd), and a
+  `+ Nieuwe registratie` button. Each row: worker · activity · type · worked (+ pauze) · date.
+  **Active** rows show `[Stop]` `[Annuleer]`; **all** rows show ✎ edit.
+- **`components/SessionForm.tsx`** — shared create/edit form: worker picker (create only, from
+  `useAdminUsers`), activity dropdown, insole-type, pair count, start/end datetime-local, paused,
+  status (edit only), notes, and a live **"gewerkt"** preview. Submits create or update.
+- **`api/admin-sessions.ts`** — add `useAllSessions`, `useAdminUsers`, `useCreateManualSession`,
+  `useUpdateSession`, `useAdminStopSession`, `useAdminDiscardSession` (all invalidate the
+  `['admin','sessions']` query family; keep the existing `useActiveSessions`).
+- **`screens/Live.tsx`** — add `[Stop]` `[Annuleer]` to each `LiveCard`, wired to the admin
+  stop/discard hooks (invalidate the active query).
+
+## C. Worker convergence (`apps/worker`)
+
+- **`api/sessions.ts`** — give `useActiveSessions` a `refetchInterval: 15000` (poll), plus the
+  default refetch-on-window-focus.
+- **`screens/Stopwatch.tsx`** — extend the active-session effect to **reconcile**: if a session is
+  running locally (`sessionId` set) but the latest `activeSessionsQuery.data` no longer contains a
+  matching **active** session for it, the session was stopped/cancelled elsewhere → reset the
+  timer and surface a brief notice **"Deze sessie is door de beheerder gestopt."** Also: treat a
+  **409** from the worker's own stop/discard as already-closed → reset locally instead of erroring.
+
+## Error handling
+
+- Worker reconciliation notice is transient (dismissible / auto-clears on next start).
+- Admin form: inline validation errors mirror the API 400s (end before start, count < 1).
+- Stop/discard on a non-active session → 409; admin UI refetches and the row reflects truth.
+
+## Testing
+
+- **API** (`admin.test.ts`): create computes duration + `source='manual'`; edit recomputes and
+  rejects `end<start`; stop/discard act on **another** user's session; all 401/403 gated;
+  `GET /api/admin/users` returns the roster.
+- **Admin:** Sessions list renders + status filter; create form posts the right body; edit
+  prefills + PUTs; Live `Stop`/`Annuleer` fire the right mutations.
+- **Worker:** when the active query returns without a locally-running session, the stopwatch
+  resets + shows the notice; a 409 on stop resets instead of erroring.
+
+## Out of scope (later 3b cycles)
+
+- Aggregated/on-screen **reporting** + all-users filtered CSV (reports cycle).
+- Full **user management** UI — create/role/deactivate via `/api/auth/admin/*` (user-mgmt cycle);
+  this cycle only *reads* the roster (`GET /api/admin/users`) for the picker.
+- Real-time push (SSE) — polling is sufficient at this scale.
+
+## Build approach
+
+spec → `writing-plans` → one **Workflow** (~7 TDD tasks), commit per task, final verify. Tracked
+as a Plane epic.