fix(universe): a moons view relaxes the dimming of orbits outside its family as the camera pulls back

[alowpoly]

With a moons view selected (for example the Earth–Moon system), every orbit outside the family stayed at 25% at every camera distance. Zooming out from Earth or the Moon selects that view on its own at about 560,000 km, so the planets' orbits stayed dim across the Solar System. The dimming now eases away between half and twice the host's distance from its star, as it already did on a body's page; up close nothing changes. The rule is outsideFamilyOrbitOpacity in context-presentation-policy.ts, stated in universe-labels.md.

Proves the change: the stroke opacity of the planets' orbits while zooming out of /earth/ and /jupiter/, read in headless Chrome at 1440 × 900. A planet's normal value is 0.65. Before: a dev server whose policy and planner files match main; css.earth reads the same for Earth. After: this branch's own build.

Moons view, altitude	Before	After
Earth, 0.23 AU	0.16	0.16
Earth, 1.2 AU	0.16	0.52
Earth, 2.8 to 69 AU	0.16	0.65
Jupiter, 2.7 AU	0.16	0.16
Jupiter, 6.3 AU	0.16	0.49
Jupiter, 14 to 71 AU	0.16	0.65

world-context-system-selection.test.ts now expects Jupiter's moons view, 6.7 AU out, to show Saturn's and Jupiter's orbits at the page's eased value (0.797); main gives 0.25 there.

Clean: renderer world-context and policy tests (86), site/test/prepared-world-context.test.ts (115), pnpm typecheck:renderer, eslint on the changed files.

Limits: not run on other browser engines, the iPad or the rendered-page suites. No image; the evidence is the measured opacity.

PR rules: titles, PDS4 provenance and ISO plain language.