Function register_clock_report_theme_elements 

pub fn register_clock_report_theme_elements(
    reg: &dyn ThemeRegistry,
    owner: ElementOwner,
) -> ClockReportElementIds

Register the report’s two theme elements and return their interned ids.

Owned by the mode, not by core: nothing outside this report paints these, and the host has no business naming an element only the clock report uses. Idempotent by name, so a re-activation re-interns rather than duplicating.

subtext and text rather than hex: a hardcoded grey survives :colorscheme and then sits at the top of the view in the previous theme’s palette, which is the one place a stale colour is impossible to miss. The total takes the brighter role because it is the row people actually read; the tree takes the muted one because it is context.