* fix(popup): align dashboard summary metrics

Use equal dashboard summary columns and the same label spacing and theme font as Cost summaries. Reveal elided KPI text on hover and exercise both columns in the synthetic smoke scenario.

Documentation: update Usage and Development guides and Unreleased notes. TODO is unchanged because this polishes supported presentation without completing a parity entry or changing CLI contracts.

* fix(popup): refine identified subtotal hierarchy

Match the optional identified-subtotal heading to neighbouring sections and emphasize its loaded total while keeping the unloaded placeholder secondary.

Documentation: update the Usage guide, its existing synthetic screenshot, and Unreleased notes. No CLI contract or TODO parity entry changes.