Claumon

Features

• Forecast trajectory modal. Click "Projected X% at reset" on a session or weekly gauge to open a modal showing the actual Monte Carlo trajectories the §6 simulator is producing: a fog of ~120 sampled paths, the empirical 10/90 percentile band traced from the same paths, the posterior mean line, observed snapshots so far, and a small first-passage histogram on the threshold line with the MC median ETA. New endpoint GET /api/forecast/sample?gauge=session|weekly re-runs the MC with trajectories collected; payload is subsampled in both the trajectory and time dimensions so weekly stays under ~200KB. The §6 MC core is shared with EstimateETA so the modal and the cached ETA summary always agree.

• Versioned forecast model. The forecast spec now carries a forecast.ModelVersion identifier (v1.0 today). It's surfaced on every /api/forecast and /api/forecast/sample response, in the modal subtitle, and in the diagnostics report. Retired specs will move to internal/forecast/archive/<version>/ when the model changes meaningfully; internal/forecast/CHANGELOG.md summarises each bump.

• claumon diagnostics subcommand. Replays the forecaster across past completed sessions and prints calibration metrics (80% CI coverage, MAE of F, ETA accuracy) stamped with the model version. Useful for deciding whether a model change actually improves accuracy before shipping it.

Internals

• CI workflows bumped to Node-24-compatible action versions (actions/checkout v4→v6, actions/setup-go v5→v6, goreleaser/goreleaser-action v6→v7); workflow Go version aligned to go.mod (1.26).