Replace the demo cone on Morning service with a real, seeded Monte Carlo
forecast over the open backlog. The LLM never does this — it's plain,
reproducible code (evidence-based scheduling).
core (@commitea/core/forecast-v0):
- Code-resident lognormal cold-start priors per estimate bucket (D3):
sampled actual = estimate * exp(N(mu, sigma)), mu > 0 (actuals run long),
sigma shrinks as tickets grow. Replaced by the team's empirical fit at
n >= 20 (#5 supplies the actuals).
- forecast(): seeded mulberry32 + Box-Muller over the scheduler's
deterministic order (order is fixed from estimates/deps; only durations
vary, so the cone stretches, never reorders). Returns p50/p80/p95 landing
+ a per-issue burn-up curve (p10/p50/p90). 12 unit tests; reproducible.
renderer:
- lib/dates.ts: working-day -> calendar mapper (skips weekends) + buildBurnUpData.
- BurnUpCone gains a data-driven twin; falls back byte-identical to the
fixture cone when no forecast (demo mode unchanged).
- Focus card shows the real "80% of the open backlog lands by <range>",
real scope count, and names the cold-start priors.
v0 scope (each a later slice): single serial worker (capacity is #8);
cold-start priors only (empirical fit is #5); no historical actual polyline
(needs lifecycle events, #5). Header chrome (reconcile time, ahead/behind
badge) stays fixture until milestone due dates land.
Verified: 51 core tests green, desktop typecheck clean, 14 fixture e2e green,
live spec asserts the real cone renders (25 open issues, "lands by Nov 11-27").
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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