476342d7b1
Hardens the families-comparison chart page (#107) so it is openable and legible on real multi-year data. Two halves, both confined to the CLI render path (engine + registry untouched, C14): #108 — serve-time min-max decimation. A pure `decimate(ChartData, buckets)` transform partitions the shared union-ts spine into <=~2000 buckets and emits each series' per-bucket min+max (nulls preserved), bounding the served page to a few thousand points regardless of the underlying M1 point count. Applied in emit_chart on both the single-run and family paths; a no-op under budget (every existing fixture). Full recorded data stays on disk; only the page is thinned. For a walk-forward family the null-fill blow-up collapses for free (an all-null bucket stays null). Deterministic (C1). #102 — a run-context header. A `ChartMeta` (name/commit/window/broker/seed/taps, + member count for a family, + bound params for a single run) is built from the RunManifest in build_chart_data / build_comparison_chart_data (which gain a `name` arg), injected into window.AURA_TRACES.meta, and rendered by a new pure buildHeader in chart-viewer.js (headless .mjs-guarded). The family window is the SPAN across members (min from, max to), not the first member's window — the only reading that labels a disjoint walk-forward family's true OOS coverage (it collapses to the shared window for sweep/MC). Reuses the existing render_value for param display (no new Scalar Display, keeping C7's tag-only param plane). The earlier "manifest is NOT carried into the page" render pin is flipped to a positive one. Verified: cargo test --workspace = 446 passed / 0 failed; cargo clippy --workspace --all-targets -D warnings clean. New coverage: 5 decimate unit tests, single-run + family meta wiring (incl. the span-window invariant), a buildHeader headless guard, and two end-to-end cli_run tests pinning the served-page meta at the binary boundary. closes #108 closes #102