v0.15.0

Changed

• Instrument-panel design language — full visual refresh of both themes, no functional changes. Light theme becomes a lab-instrument panel (warm greys #edece7, panel-white cards, amber accent #a16207); dark theme becomes a cockpit (near-black ground #0d0e0c, amber phosphor accent #ffb454, instrument palette for positive/negative). Hero numbers and chart axis text now use monospace numerals, corners squared (6px → 3px), and the content ground carries a faint engineering grid.
• New --accent-fg token — text on accent-colored surfaces (period buttons, calendar, compare tabs, update banner, flowchart output node) resolves to white in light theme and dark umber in dark theme, keeping contrast on the amber accent.
• billboard.js 4.0.3 — dependency bump from 4.0.1.

Fixed

• Update banner covered the page title — the fixed top banner (update / partial / first-run) now pushes the content down instead of overlaying the page header.
• DEV BUILD badge overlapped the banner's refresh button — badge moved to the bottom-right corner.
• Structure flowchart ignored dark theme — drawFlowchart() read CSS variables from documentElement, but dark-theme overrides live on body.dark; it now reads from body, so the flow diagram follows the active theme.