feat: capacity-aware scheduling (#8) — real focus factors drive every forecast

Turns the single-serial-worker scheduler into a capacity-aware, multi-lane one.
Configured team members become lanes; an issue runs on its assignee's lane (or the
earliest-free lane), its duration scaled by that lane's throughput
(focusFactor × allocation). Every forecast — Focus cone, Runway, milestone
drill-in — is now capacity-aware.

core (@commitea/core):
- capacity/capacity-v0: CapacityMember + capacityPerWorkday + parseCapacityConfig
  (clamps, drops invalid; degrades to []).
- scheduler/scheduler-capacity-v0: scheduleWithCapacity reuses the v0 topo order +
  critical path, re-lays work across lanes (layoutOnLanes, resolveLanes, makespan).
  Empty workers → the single serial plan verbatim.
- forecast() gains options.workers: each MC trial lays sampled durations across the
  lanes and takes the makespan; serial path unchanged. SchedulableIssue gains
  assignee; ScheduledItem gains worker.
- 11 new tests (parse/clamp, parallelism halves makespan, speed scaling, assignee
  routing, cross-lane deps, forecast makespan shrinks with lanes).

app:
- pm-state capacity/members.json read (readCapacity + pmstate:capacity bridge);
  useCapacity hook → workers; forecastBacklog/runwayView/milestoneView pass workers.
- Runway Capacity card shows the real config (person · focus · alloc · pd/day).

Config lives in pm-state (D4); seeded christian(0.8)/stephen(0.6×0.5). Degrades to
the fixture/serial when absent.

Verified: 128 core tests green, desktop typecheck clean, 14 fixture e2e green. Live:
the capacity card is real, and the P2 forecast shifts 32d→37d — honest, since real
focus factors (<1) replace the v0 focus-1.0 assumption.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

packages/core/src/scheduler/scheduler-capacity-v0.ts

@@ -0,0 +1,119 @@
+/**
+ * Capacity-aware scheduler (#8). Reuses the single-worker scheduler's topological
+ * order + critical-path marking, then re-lays the work across lanes: an issue
+ * runs on its assignee's lane (or the earliest-free lane when unassigned), its
+ * duration scaled by that lane's speed (ideal person-days/workday). Makespan
+ * shrinks toward the critical path as lanes are added. Deterministic; falls back
+ * to the single serial worker when no capacity is configured. The lane layout is
+ * factored so the Monte Carlo forecast reuses it per trial with sampled durations.
+ */
+
+import {
+  type DependencyEdge,
+  schedule,
+  type SchedulableIssue,
+  type SchedulePlan,
+} from './scheduler-v0.js'
+
+/** A scheduling lane: a person and their throughput (ideal person-days / workday). */
+export interface Worker {
+  person: string
+  speed: number
+}
+
+/** The topological order + per-issue relations the layout needs (from the base plan). */
+export interface LaneInputs {
+  order: number[]
+  blockedBy: Map<number, number[]>
+  assignee: Map<number, string | null>
+}
+
+/** Ensure a lane exists for every assignee; unconfigured assignees get the mean speed. */
+export function resolveLanes(workers: Worker[], assignees: (string | null)[]): Worker[] {
+  const lanes = [...workers]
+  const known = new Set(lanes.map((w) => w.person))
+  const meanSpeed = lanes.length ? lanes.reduce((s, w) => s + w.speed, 0) / lanes.length : 1
+  for (const a of assignees) {
+    if (a && !known.has(a)) {
+      lanes.push({ person: a, speed: meanSpeed })
+      known.add(a)
+    }
+  }
+  return lanes
+}
+
+function pickWorker(lanes: Worker[], freeAt: Map<string, number>, assignee: string | null | undefined): Worker {
+  if (assignee) {
+    const own = lanes.find((w) => w.person === assignee)
+    if (own) return own
+  }
+  let best = lanes[0]
+  for (const w of lanes) if (freeAt.get(w.person)! < freeAt.get(best.person)!) best = w
+  return best
+}
+
+/**
+ * Lay a topologically-ordered set out across lanes. `duration(n)` supplies each
+ * issue's duration for this layout (estimate, or a sampled value in a MC trial).
+ * Returns each issue's finish day + the lane it ran on. Order guarantees a
+ * dependency is always laid out before its dependents.
+ */
+export function layoutOnLanes(
+  inputs: LaneInputs,
+  lanes: Worker[],
+  duration: (n: number) => number,
+): { finishAt: Map<number, number>; startAt: Map<number, number>; laneOf: Map<number, string> } {
+  const freeAt = new Map(lanes.map((w) => [w.person, 0]))
+  const finishAt = new Map<number, number>()
+  const startAt = new Map<number, number>()
+  const laneOf = new Map<number, string>()
+  for (const n of inputs.order) {
+    const worker = pickWorker(lanes, freeAt, inputs.assignee.get(n))
+    const blockers = inputs.blockedBy.get(n) ?? []
+    const depFinish = blockers.length ? Math.max(...blockers.map((d) => finishAt.get(d) ?? 0)) : 0
+    const start = Math.max(freeAt.get(worker.person)!, depFinish)
+    const end = start + duration(n) / worker.speed
+    startAt.set(n, start)
+    finishAt.set(n, end)
+    laneOf.set(n, worker.person)
+    freeAt.set(worker.person, end)
+  }
+  return { finishAt, startAt, laneOf }
+}
+
+/**
+ * Capacity-aware plan. An empty `workers` means no capacity is configured → the
+ * single-worker plan verbatim.
+ */
+export function scheduleWithCapacity(
+  issues: SchedulableIssue[],
+  edges: DependencyEdge[],
+  workers: Worker[],
+): SchedulePlan {
+  if (workers.length === 0) return schedule(issues, edges)
+  const base = schedule(issues, edges)
+  if (base.cycle || base.items.length === 0) return base
+
+  const inputs: LaneInputs = {
+    order: base.items.map((it) => it.number),
+    blockedBy: new Map(base.items.map((it) => [it.number, it.blockedBy])),
+    assignee: new Map(issues.map((i) => [i.number, i.assignee ?? null])),
+  }
+  const lanes = resolveLanes(workers, [...inputs.assignee.values()])
+  const durationOf = new Map(base.items.map((it) => [it.number, it.durationDays]))
+  const { finishAt, startAt, laneOf } = layoutOnLanes(inputs, lanes, (n) => durationOf.get(n)!)
+
+  const items = base.items.map((it) => ({
+    ...it,
+    startDay: startAt.get(it.number)!,
+    endDay: finishAt.get(it.number)!,
+    durationDays: finishAt.get(it.number)! - startAt.get(it.number)!,
+    worker: laneOf.get(it.number),
+  }))
+  return { items, cycle: null }
+}
+
+/** Makespan (last finish) of a plan — the project's landing day. */
+export function makespan(plan: SchedulePlan): number {
+  return plan.items.reduce((m, it) => Math.max(m, it.endDay), 0)
+}