Brummel
be71f0a55c
Tier-1 comfort pass for the served trace chart (#103): an ordinal x-axis default (collapses non-trading gaps) with a one-click continuous toggle, plus wheel-zoom / drag-pan / dblclick-reset, a value-readout legend, and panel cursor-sync. Confined to the read/render side (chart-viewer.js + render.rs CHART_HEAD); the Rust serve contract is unchanged. Boss-signed: grounding-check PASS (five current-behaviour assumptions ratified by green node guards + render.rs inline tests). Derived-fork decision log in the #103 comments. refs #103