Merge pull request 'feat: capacity-aware scheduling (#8) — real focus factors drive every forecast' (#50) from feat/capacity into main

Reviewed-on: #50

apps/desktop/e2e/live-backlog.spec.ts

@@ -44,6 +44,9 @@ test.describe('live backlog', () => {
     // Real per-milestone forecasts — these milestone names come from gitea, not the
     // fixture (which lists Beta / Pilot-ready / v1.0).
     await expect(win.getByText(/P2 — Scheduler/)).toBeVisible()
+    // Real capacity config from pm-state (christian/stephen), not the fixture (Stephen/Ana K.)
+    await expect(win.getByText('christian', { exact: true })).toBeVisible()
+    await expect(win.getByText(/pd\/day/).first()).toBeVisible()
     await win.screenshot({ path: join(here, '.artifacts', 'screens', 'live-runway.png'), fullPage: true, animations: 'disabled' })
 
     // Milestone drill-in — clicking a real milestone opens its real detail

apps/desktop/src/main/gitea.ts

@@ -20,6 +20,7 @@ import {
   type IssueChange,
   type LifecycleEvent,
   makeDirectiveEntry,
+  parseCapacityConfig,
   parseDirectiveLog,
   planIssueChange,
   type ProjectSnapshot,
@@ -109,6 +110,19 @@ export async function readDirectives(client: GiteaClient) {
   return parseDirectiveLog(text)
 }
 
+const CAPACITY_PATH = 'capacity/members.json'
+
+/** Read the capacity config from the pm-state repo (empty when absent). */
+export async function readCapacity(client: GiteaClient) {
+  const file = await client.getFile(CAPACITY_PATH)
+  if (!file) return []
+  try {
+    return parseCapacityConfig(JSON.parse(Buffer.from(file.contentBase64, 'base64').toString('utf8')))
+  } catch {
+    return []
+  }
+}
+
 /** Full reconcile: issues + milestones + native deps + lifecycle timelines. */
 export async function reconcileSnapshot(
   client: GiteaClient,
@@ -266,4 +280,15 @@ export function registerGiteaIpc(): void {
       return { ok: false as const, reason: 'error' as const, message: e instanceof Error ? e.message : String(e) }
     }
   })
+
+  // Read the capacity config from the pm-state repo (for capacity-aware forecasts).
+  ipcMain.handle('pmstate:capacity', async () => {
+    const pm = getPmStateClient()
+    if (!pm) return { ok: false as const, reason: 'unconfigured' as const, members: [] }
+    try {
+      return { ok: true as const, members: await readCapacity(pm) }
+    } catch {
+      return { ok: true as const, members: [] }
+    }
+  })
 }

apps/desktop/src/preload/index.ts

@@ -19,6 +19,8 @@ const api = {
   pmstate: {
     /** Read the directive ledger from the pm-state repo. */
     directives: () => ipcRenderer.invoke('pmstate:directives'),
+    /** Read the capacity config from the pm-state repo. */
+    capacity: () => ipcRenderer.invoke('pmstate:capacity'),
   },
   model: {
     /** Whether a model endpoint is configured (else the UI keeps the scripted Reginald). */

apps/desktop/src/renderer/src/components/screens/runway-screen.tsx

@@ -1,23 +1,35 @@
 import React from 'react'
 
+import { type CapacityMember, capacityPerWorkday } from '@commitea/core'
+
 import { RunwayBar } from '../charts/chart.js'
 import { Card, Badge, Tag, Icon, IconButton } from '../ui/index.js'
 import { RUNWAY, CAPACITY, type RunwayMilestone } from '../../data/fixtures.js'
 
 // Runway — capacity vs milestone dates; ranges, never points.
-// `milestones` (real per-milestone forecasts) overrides the demo when present.
+// `milestones` (real per-milestone forecasts) + `capacity` (real config) override the demo.
 export function RunwayScreen({
   onOpenCalibration,
   onOpenMilestone,
   calibration,
   milestones,
+  capacity,
 }: {
   onOpenCalibration: () => void
   onOpenMilestone: (id?: number) => void
   calibration?: { n: number; coldStart: boolean }
   milestones?: RunwayMilestone[]
+  capacity?: CapacityMember[]
 }) {
   const rows = milestones && milestones.length ? milestones : RUNWAY
+  const capacityRows =
+    capacity && capacity.length
+      ? capacity.map((m) => ({
+          who: m.person,
+          slices: `focus ${m.focusFactor} · alloc ${Math.round(m.allocation * 100)}%`,
+          hours: `${capacityPerWorkday(m).toFixed(2)} pd/day`,
+        }))
+      : CAPACITY
   const calibNote = calibration
     ? calibration.coldStart
       ? `cold-start priors · ${calibration.n}/20 closed issues estimated`
@@ -59,7 +71,7 @@ export function RunwayScreen({
       <div style={{ display: 'grid', gridTemplateColumns: '1fr 1fr', gap: 14, alignItems: 'start' }}>
         <Card overline="Capacity" flush>
           <div>
-            {CAPACITY.map((p, i) => (
+            {capacityRows.map((p, i) => (
               <div key={p.who} style={{
                 display: 'flex', alignItems: 'center', gap: 12, padding: '12px 20px',
                 borderTop: i === 0 ? 'none' : '1px solid var(--line-1)',

apps/desktop/src/renderer/src/components/shell/app-shell.tsx

@@ -6,6 +6,7 @@ import type { IssueChange } from '@commitea/core'
 import type { IssueRef } from '../../data/fixtures.js'
 import {
   backlogCalibration,
+  capacityWorkers,
   forecastBacklog,
   issuesToBoardColumns,
   milestoneView,
@@ -13,6 +14,7 @@ import {
   scheduleFocus,
 } from '../../lib/backlog.js'
 import { useBacklog } from '../../lib/use-backlog.js'
+import { useCapacity } from '../../lib/use-capacity.js'
 import { PrimitivesGallery } from '../gallery.js'
 import { BoardScreen } from '../screens/board-screen.js'
 import { CalibrationScreen } from '../screens/calibration-screen.js'
@@ -96,6 +98,8 @@ export function AppShell() {
   const [readIds, setReadIds] = useState<number[]>([])
   const [milestoneId, setMilestoneId] = useState<number | null>(null)
   const [backlog, refetchBacklog] = useBacklog()
+  const capacityMembers = useCapacity()
+  const workers = capacityWorkers(capacityMembers)
   const boardColumns =
     backlog.status === 'ready' ? issuesToBoardColumns(backlog.issues, backlog.timelines) : undefined
   const focus =
@@ -104,10 +108,12 @@ export function AppShell() {
     backlog.status === 'ready' ? backlogCalibration(backlog.issues, backlog.timelines) : undefined
   const forecast =
     backlog.status === 'ready'
-      ? (forecastBacklog(backlog.issues, backlog.deps, new Date(), calibration?.model) ?? undefined)
+      ? (forecastBacklog(backlog.issues, backlog.deps, new Date(), calibration?.model, workers) ?? undefined)
       : undefined
   const runwayMilestones =
-    backlog.status === 'ready' ? runwayView(backlog.issues, backlog.milestones, backlog.deps) : undefined
+    backlog.status === 'ready'
+      ? runwayView(backlog.issues, backlog.milestones, backlog.deps, new Date(), workers)
+      : undefined
   const milestone =
     backlog.status === 'ready' && milestoneId != null
       ? (milestoneView(
@@ -117,6 +123,8 @@ export function AppShell() {
           backlog.deps,
           backlog.timelines,
           calibration?.model,
+          new Date(),
+          workers,
         ) ?? undefined)
       : undefined
 
@@ -221,6 +229,7 @@ export function AppShell() {
             }}
             calibration={calibration ? { n: calibration.model.n, coldStart: calibration.model.coldStart } : undefined}
             milestones={runwayMilestones}
+            capacity={capacityMembers}
           />
         )
       case 'calibration':

apps/desktop/src/renderer/src/global.d.ts

@@ -1,5 +1,6 @@
 import type {
   AgentStep,
+  CapacityMember,
   ChangeProposal,
   ChatMessage,
   CaptureProposal,
@@ -77,9 +78,15 @@ export type DirectivesResult =
   | { ok: false; reason: 'unconfigured' | 'error'; message?: string }
   | { ok: true; directives: DirectiveRecord[] }
 
+/** The result of reading the capacity config. */
+export type CapacityResult =
+  | { ok: false; reason: 'unconfigured'; members: CapacityMember[] }
+  | { ok: true; members: CapacityMember[] }
+
 /** The pm-state bridge (machine-derived state) exposed by the preload over IPC. */
 export interface PmStateBridge {
   directives(): Promise<DirectivesResult>
+  capacity(): Promise<CapacityResult>
 }
 
 declare global {

apps/desktop/src/renderer/src/lib/backlog.ts

@@ -2,10 +2,13 @@ import {
   type CalibrationModel,
   type CalibrationSample,
   calibrationSamples,
+  type CapacityMember,
+  capacityPerWorkday,
   COLD_START_THRESHOLD,
   type DependencyEdge,
   fitCalibration,
   forecast,
+  type Worker,
   type GiteaIssue,
   type GiteaMilestone,
   inferLifecycle,
@@ -107,9 +110,15 @@ function toSchedulable(issues: GiteaIssue[]) {
       labels: i.labels,
       estimateDays: i.facts.estimateDays,
       priority: i.facts.priority,
+      assignee: i.assignee,
     }))
 }
 
+/** gitea CapacityMembers → scheduler lanes (person + throughput). */
+export function capacityWorkers(members: CapacityMember[]): Worker[] {
+  return members.map((m) => ({ person: m.person, speed: capacityPerWorkday(m) }))
+}
+
 export interface ForecastView {
   scope: number
   cone: BurnUpData
@@ -132,9 +141,10 @@ export function forecastBacklog(
   deps: DependencyEdge[],
   today: Date = new Date(),
   calibration?: CalibrationModel,
+  workers: Worker[] = [],
 ): ForecastView | null {
   const model = calibration ? toDurationModel(calibration) : undefined
-  const f = forecast(toSchedulable(issues), deps, model ? { model } : {})
+  const f = forecast(toSchedulable(issues), deps, { ...(model ? { model } : {}), workers })
   const cone = buildBurnUpData(f, today)
   if (!cone) return null
   return {
@@ -252,6 +262,7 @@ export function runwayView(
   milestones: GiteaMilestone[],
   deps: DependencyEdge[],
   today: Date = new Date(),
+  workers: Worker[] = [],
 ): RunwayMilestone[] {
   const open = issues.filter((i) => i.state === 'open')
   const rows = milestones
@@ -266,8 +277,10 @@ export function runwayView(
           labels: i.labels,
           estimateDays: i.facts.estimateDays,
           priority: i.facts.priority,
+          assignee: i.assignee,
         })),
         deps,
+        { workers },
       )
       const p90 = f.curve.length ? f.curve[f.curve.length - 1].p90Day : f.p95Day
       const dueDay = m.dueOn ? workingDaysBetween(today, new Date(m.dueOn)) : null
@@ -324,6 +337,7 @@ export function milestoneView(
   timelines: Timelines = {},
   calibration?: CalibrationModel,
   today: Date = new Date(),
+  workers: Worker[] = [],
 ): MilestoneView | null {
   const m = milestones.find((x) => x.id === id)
   if (!m) return null
@@ -340,9 +354,10 @@ export function milestoneView(
       labels: i.labels,
       estimateDays: i.facts.estimateDays,
       priority: i.facts.priority,
+      assignee: i.assignee,
     })),
     deps,
-    model ? { model } : {},
+    { ...(model ? { model } : {}), workers },
   )
   const cone = buildBurnUpData(f, today)
 

apps/desktop/src/renderer/src/lib/use-capacity.ts

@@ -0,0 +1,24 @@
+import { useEffect, useState } from 'react'
+
+import type { CapacityMember } from '@commitea/core'
+
+/**
+ * The team's capacity config from the pm-state repo. Empty when unconfigured —
+ * forecasts then fall back to a single serial worker. Read once on mount.
+ */
+export function useCapacity(): CapacityMember[] {
+  const [members, setMembers] = useState<CapacityMember[]>([])
+  useEffect(() => {
+    let alive = true
+    window.commitea.pmstate
+      .capacity()
+      .then((r) => {
+        if (alive) setMembers(r.members)
+      })
+      .catch(() => {})
+    return () => {
+      alive = false
+    }
+  }, [])
+  return members
+}

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

@@ -0,0 +1,88 @@
+import { describe, expect, it } from 'vitest'
+
+import { type DependencyEdge, type SchedulableIssue } from '../scheduler/scheduler-v0.js'
+import { makespan, scheduleWithCapacity, type Worker } from '../scheduler/scheduler-capacity-v0.js'
+import { capacityPerWorkday, parseCapacityConfig } from './capacity-v0.js'
+
+describe('capacity model', () => {
+  it('capacityPerWorkday = focusFactor × allocation', () => {
+    expect(capacityPerWorkday({ person: 'a', focusFactor: 0.8, allocation: 0.5 })).toBeCloseTo(0.4)
+  })
+
+  it('parses + clamps config, drops invalid members', () => {
+    const members = parseCapacityConfig({
+      members: [
+        { person: 'christian', focusFactor: 0.8, allocation: 1 },
+        { person: 'ak', focusFactor: 1.5, allocation: -1 }, // clamps to 1 / 0 → zero capacity → dropped
+        { focusFactor: 0.8 }, // no person → dropped
+      ],
+    })
+    expect(members).toEqual([{ person: 'christian', focusFactor: 0.8, allocation: 1 }])
+  })
+
+  it('returns [] for a non-array/absent members field', () => {
+    expect(parseCapacityConfig({})).toEqual([])
+    expect(parseCapacityConfig({ members: 'nope' })).toEqual([])
+  })
+})
+
+function issue(number: number, over: Partial<SchedulableIssue> = {}): SchedulableIssue {
+  return { number, title: `#${number}`, labels: [], estimateDays: 4, priority: 2, ...over }
+}
+
+describe('scheduleWithCapacity', () => {
+  it('with no workers, falls back to the single serial plan', () => {
+    const issues = [issue(1), issue(2)]
+    const plan = scheduleWithCapacity(issues, [], [])
+    expect(makespan(plan)).toBe(8) // 4 + 4 serial
+  })
+
+  it('parallelizes independent work across lanes (makespan shrinks)', () => {
+    const issues = [issue(1), issue(2), issue(3), issue(4)] // 4×4d = 16d serial
+    const one: Worker[] = [{ person: 'a', speed: 1 }]
+    const two: Worker[] = [
+      { person: 'a', speed: 1 },
+      { person: 'b', speed: 1 },
+    ]
+    expect(makespan(scheduleWithCapacity(issues, [], one))).toBe(16)
+    expect(makespan(scheduleWithCapacity(issues, [], two))).toBe(8) // two lanes → half
+  })
+
+  it('scales duration by a lane speed (slower lane takes longer)', () => {
+    const plan = scheduleWithCapacity([issue(1, { estimateDays: 4 })], [], [{ person: 'a', speed: 0.5 }])
+    expect(plan.items[0].durationDays).toBe(8) // 4 / 0.5
+    expect(plan.items[0].worker).toBe('a')
+  })
+
+  it('routes an issue to its assignee lane', () => {
+    const issues = [issue(1, { assignee: 'ak' }), issue(2, { assignee: 'sm' })]
+    const workers: Worker[] = [
+      { person: 'ak', speed: 1 },
+      { person: 'sm', speed: 1 },
+    ]
+    const plan = scheduleWithCapacity(issues, [], workers)
+    const byN = Object.fromEntries(plan.items.map((i) => [i.number, i]))
+    expect(byN[1].worker).toBe('ak')
+    expect(byN[2].worker).toBe('sm')
+    // both start at 0 (different lanes) → parallel
+    expect(byN[1].startDay).toBe(0)
+    expect(byN[2].startDay).toBe(0)
+  })
+
+  it('adds a lane for an assignee not in the config (mean speed)', () => {
+    const plan = scheduleWithCapacity([issue(1, { assignee: 'newbie' })], [], [{ person: 'a', speed: 0.5 }])
+    expect(plan.items[0].worker).toBe('newbie')
+    expect(plan.items[0].durationDays).toBe(8) // mean speed 0.5 → 4/0.5
+  })
+
+  it('respects dependencies across lanes (a blocker finishes before its dependent starts)', () => {
+    const edges: DependencyEdge[] = [{ issue: 2, dependsOn: 1 }]
+    const workers: Worker[] = [
+      { person: 'a', speed: 1 },
+      { person: 'b', speed: 1 },
+    ]
+    const plan = scheduleWithCapacity([issue(1), issue(2)], edges, workers)
+    const byN = Object.fromEntries(plan.items.map((i) => [i.number, i]))
+    expect(byN[2].startDay).toBeGreaterThanOrEqual(byN[1].endDay) // #2 waits for #1 even on another lane
+  })
+})

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

@@ -0,0 +1,49 @@
+/**
+ * Capacity model (#8). A member's throughput is `focusFactor × allocation` =
+ * ideal person-days of project work delivered per calendar working day. The
+ * scheduler treats each member as a lane whose task durations are scaled by that
+ * rate (a 0.5-capacity person takes twice as long on an est/2d task). Config
+ * lives in the pm-state repo (`capacity/members.yaml/json`, D4); estimates are
+ * in ideal person-days (pm-state.md).
+ */
+
+export interface CapacityMember {
+  /** gitea login. */
+  person: string
+  /** Productive fraction of a working day (0..1). */
+  focusFactor: number
+  /** Fraction of that allocated to this project (0..1). */
+  allocation: number
+}
+
+/** Ideal person-days delivered per calendar working day. */
+export function capacityPerWorkday(m: CapacityMember): number {
+  return m.focusFactor * m.allocation
+}
+
+function clamp01(n: unknown, fallback: number): number {
+  return typeof n === 'number' && Number.isFinite(n) ? Math.min(1, Math.max(0, n)) : fallback
+}
+
+/**
+ * Validate a raw capacity config (`{ members: [...] }`) into members. Unknown
+ * shapes degrade to `[]` (→ the scheduler falls back to a single worker), never
+ * throw. focusFactor/allocation clamp to [0,1]; a member without a person is dropped.
+ */
+export function parseCapacityConfig(raw: unknown): CapacityMember[] {
+  const list = (raw as { members?: unknown })?.members
+  if (!Array.isArray(list)) return []
+  const out: CapacityMember[] = []
+  for (const m of list) {
+    const r = (m ?? {}) as Record<string, unknown>
+    const person = typeof r.person === 'string' ? r.person.trim() : ''
+    if (!person) continue
+    const member: CapacityMember = {
+      person,
+      focusFactor: clamp01(r.focusFactor, 0.8),
+      allocation: clamp01(r.allocation, 1),
+    }
+    if (capacityPerWorkday(member) > 0) out.push(member)
+  }
+  return out
+}

packages/core/src/forecast/forecast-v0.test.ts

@@ -120,4 +120,20 @@ describe('forecast', () => {
     expect(fitted.coldStart).toBe(false)
     expect(fitted.p50Day).toBeLessThan(priors.p50Day)
   })
+
+  it('capacity lanes parallelize the sim — the makespan shrinks with more workers', () => {
+    const independent = [issue(1), issue(2), issue(3), issue(4)] // no deps → fully parallelizable
+    const serial = forecast(independent, [], { trials: 2000, seed: 7 })
+    const twoLanes = forecast(independent, [], {
+      trials: 2000,
+      seed: 7,
+      workers: [
+        { person: 'a', speed: 1 },
+        { person: 'b', speed: 1 },
+      ],
+    })
+    // two equal lanes ≈ half the serial landing (independent work)
+    expect(twoLanes.p80Day).toBeLessThan(serial.p80Day)
+    expect(twoLanes.p80Day).toBeLessThan(serial.p80Day * 0.7)
+  })
 })

packages/core/src/forecast/forecast-v0.ts

@@ -18,6 +18,7 @@ import {
   schedule,
   type SchedulableIssue,
 } from '../scheduler/scheduler-v0.js'
+import { type LaneInputs, layoutOnLanes, resolveLanes, type Worker } from '../scheduler/scheduler-capacity-v0.js'
 
 export interface LognormalPrior {
   /** Median log-ratio: sampled median duration = estimate * e^mu. */
@@ -76,6 +77,12 @@ export interface ForecastOptions {
    * the sim; otherwise the code-resident cold-start priors do.
    */
   model?: DurationModel
+  /**
+   * Capacity lanes. When provided, each trial lays sampled durations across the
+   * lanes (parallel) instead of a single serial worker — the makespan shrinks
+   * toward the critical path. Empty/absent → single serial worker.
+   */
+  workers?: Worker[]
 }
 
 /** Resolve the lognormal params for an estimate, preferring a fitted model. */
@@ -158,17 +165,34 @@ export function forecast(
   const priors = order.map((it) => durationParams(it.durationDays, options.model))
   const rng = mulberry32(seed)
 
-  // endByRank[k][t] = working day the (k+1)-th scheduled issue completes on trial t.
+  // Capacity lanes, when configured — the per-trial layout goes parallel.
+  const laneInputs: LaneInputs = {
+    order: order.map((it) => it.number),
+    blockedBy: new Map(order.map((it) => [it.number, it.blockedBy])),
+    assignee: new Map(issues.map((i) => [i.number, i.assignee ?? null])),
+  }
+  const lanes =
+    options.workers && options.workers.length ? resolveLanes(options.workers, [...laneInputs.assignee.values()]) : null
+
+  // endByRank[k][t] = working day the (k+1)-th issue *to finish* completes on trial t.
   const endByRank: number[][] = Array.from({ length: n }, () => new Array<number>(trials))
   for (let t = 0; t < trials; t++) {
+    const sampled = order.map((it, k) => it.durationDays * Math.exp(priors[k].mu + priors[k].sigma * standardNormal(rng)))
+    if (lanes) {
+      // parallel: lay the sampled durations across lanes, then sort finish days
+      const byNumber = new Map(order.map((it, k) => [it.number, sampled[k]]))
+      const { finishAt } = layoutOnLanes(laneInputs, lanes, (num) => byNumber.get(num)!)
+      const finishes = order.map((it) => finishAt.get(it.number)!).sort((a, b) => a - b)
+      for (let k = 0; k < n; k++) endByRank[k][t] = finishes[k]
+    } else {
+      // single serial worker: cumulative sum (already sorted ascending)
       let cursor = 0
       for (let k = 0; k < n; k++) {
-      const p = priors[k]
+        cursor += sampled[k]
-      const sampled = order[k].durationDays * Math.exp(p.mu + p.sigma * standardNormal(rng))
-      cursor += sampled
         endByRank[k][t] = cursor
       }
     }
+  }
 
   const curve: BurnUpPoint[] = endByRank.map((row, k) => {
     const sorted = [...row].sort((a, b) => a - b)

packages/core/src/index.ts

@@ -49,6 +49,12 @@ export type {
   SchedulePlan,
 } from './scheduler/scheduler-v0.js'
 
+export { makespan, scheduleWithCapacity } from './scheduler/scheduler-capacity-v0.js'
+export type { Worker } from './scheduler/scheduler-capacity-v0.js'
+
+export { capacityPerWorkday, parseCapacityConfig } from './capacity/capacity-v0.js'
+export type { CapacityMember } from './capacity/capacity-v0.js'
+
 export {
   COLD_START_PRIORS,
   durationParams,

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)
+}

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

@@ -21,6 +21,8 @@ export interface SchedulableIssue {
   estimateDays: number | null
   /** 1 (most urgent) … 4; null when unset. */
   priority: number | null
+  /** gitea assignee login, for capacity-aware lane routing; optional. */
+  assignee?: string | null
 }
 
 export interface DependencyEdge {
@@ -45,6 +47,8 @@ export interface ScheduledItem {
   /** On a longest-duration dependency chain. */
   critical: boolean
   rationale: string
+  /** Lane it's scheduled on, when capacity-aware; absent for the single-worker plan. */
+  worker?: string
 }
 
 export interface SchedulePlan {