feat(stars): show pulsating stars' light through their cycle

[alowpoly]

Change

A Cepheid's page showed one color sphere. 125 pages now have a Pulsation dataset: ten steps, a tenth of a period apart, each the star's color at that phase's share of its brightest light. The page still opens on Color. Method note.

Sources and processing

• Source: Gaia DR3 vari_cepheid (Ripepi et al. 2023): each star's published G-band Fourier model.
• Processing: the model read at ten phases; magnitudes to shares of light. Nothing is fitted.
• Limits: light only; no color or size change (no published calibration found). 49 Milky Way, 38 Magellanic, 34 M33 and 4 M31 stars; the last 38 are tied to their Gaia row by place (1 arcsecond) and period (1%), limits of ours. 352 Cepheid pages stay plain.
• Open: for 6 stars Gaia's model swings over 0.2 mag beyond Gaia's own measurements (X Pup: 1.54 mag). Drawn as published; the note lists them.

Also fixed: a star with a light-curve veil could not be prepared again since #1300.

No world step was run: on the map these stars stay plain dots until one runs.

Prepared assets

• Baked, published, inventories committed.

Evidence

Proves the change: headless Chrome on the dev site, RY CMa: each step's disc centre is its share of the star's color within one level. All 125 runtimes read back against their tables: 0 problems.

Clean: type-checks and tests of the touched packages pass; the site lane fails 6 of 1,797 locally, none naming this change.