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>

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: [] }
+    }
+  })
 }