Airframe theme-v13

The docs-site mapping catches up with theme-v12's type rule: labels are sentence-case sans, not mono capitals
(KAN-150 found them still in mono on the flightdeck site). airframe-docs.css and the DecisionDeck rules change; no token changes value,
none is added, renamed or removed.

• Tabs, nav titles, table headers, admonition and details titles, buttons, the eyebrow, figure captions, the tool-card
  kicker and the suite strip's home link and plane words are Red Hat Text 500, sentence case, no tracking.
  The strip's plane words go from .5rem to .55rem and its home link from .56rem to .6rem.
• h4–h6 are sans 600 at .75rem in fg-muted instead of small mono capitals in fg-subtle.
• Code, IDs and numbers stay in DM Mono.
• The deprecated brand-wash is gone from the docs mapping: the accent wash, <mark> and highlighted code lines
  use selected (neutral), so Day no longer shows a yellow tint.
• DecisionDeck (airframe-components.css): the cards peeking behind the top one no longer show the 3px status edge (only
  the top card carries it). New af-deck__subtitle and af-deck__stopped: what stopped (failed, denied) is listed
  under up-next as "Stopped", visible at every width, and is no longer stacked with the decisions, so "1 of N" counts
  decisions only and agrees with the nav badge (found in hangar #343). The README and preview follow.
• New af-gauge--mini (airframe-components.css): a gauge in a list keeps a neutral fg-muted limit bug; a lone gauge
  keeps the brand-text bug. Data.md states the rule (found in Tower #86).