feat(homepage): rebuild the theme on canonical Australis tokens

The predecessor theme was ugly for two structural reasons, not one.

It did not use the design system's colours. It built a parallel OKLCH
palette "derived from the Australis philosophy" and swapped the canonical
typeface for Supreme -- a fork, not a theme. Every hex here is now copied
verbatim from ~/.claude/skills/australis-design/colors_and_type.css, and
build.py re-checks all 19 against that file at build time and warns on
drift so it cannot quietly fork again. Type is the canonical stack: Space
Grotesk / Inter / JetBrains Mono, vendored as latin-subset VARIABLE woff2
(one file per family, 102 KB total against 56 KB for three static Supreme
cuts, and no Google Fonts request at page load).

It also carried a generated full-bleed aurora image behind the entire
dashboard. Canon forbids exactly that -- "solid fills only on chrome, no
full-bleed photography, no decorative gradients", and the aurora motif
"never as a background fill behind text". The predecessor knew, said so in
its own header, and dialled the opacity down rather than dropping it. The
image is gone; the aurora survives as a 1px accent edge under the tab bar,
which is where canon sanctions it. The asset stays in images/ in case it
is ever revisited.

Direction is instrument panel. Group headings become the Australis mono
eyebrow with a hairline to the right edge -- canon calls the eyebrow a
system signature, and it turns the groups into register bands instead of
headings floating over a grid. Status stops shouting: the filled emerald
chips read louder than the service names they annotated, so they are now a
semantic dot plus a mono micro-label at tertiary contrast. Cards are
bordered and opaque, per canon's border-over-shadow rule for chrome.

Alignment, per operator feedback that pills and cards did not line up:

- The status cluster is centred on the service name's line rather than
  parked in the card's top-right corner, where Homepage's `absolute top-0`
  left it floating ~7px above the title's optical centre. The offsets
  reconstruct the title line box and are documented as moving together.
- Descriptions get a two-line minimum, so the common one-line/two-line mix
  bottom-aligns across a row. This is what made the grid look ragged.
  useEqualHeights stays false: it inflated short cards to match a widget
  card twice their height, which was the worse failure.
- The status dot is flex-centred rather than nudged with vertical-align,
  so it stays centred if the type scale changes.

Retires the Skyfall sources and the Supreme faces; theme/ now has one
source of truth.

stacks/homepage/theme/layout.css

@@ -1,72 +0,0 @@
-/* Australis Skyfall — spacing, radii, shadows, motion (v3 "calm depth") */
-
-:root {
-  /* Spacing (4px base) */
-  --space-1: 4px;
-  --space-2: 8px;
-  --space-3: 12px;
-  --space-4: 16px;
-  --space-5: 20px;
-  --space-6: 24px;
-  --space-8: 32px;
-  --space-10: 40px;
-  --space-12: 48px;
-  --space-16: 64px;
-  --space-20: 80px;
-  --space-24: 96px;
-  --space-32: 128px;
-
-  /* Semantic spacing — airy content, compact chrome */
-  --pad-chrome: var(--space-2);   /* app chrome: rails, toolbars, list rows */
-  --pad-content: var(--space-8);  /* work surfaces: page bodies, card interiors breathe */
-  --gap-pane: var(--space-4);     /* gutter between panes/cards on the canvas */
-  --measure: 68ch;                /* long-form reading width */
-
-  /* Radii — moderate, calm */
-  --radius-xs: 6px;
-  --radius-sm: 8px;
-  --radius-md: 10px;  /* buttons, inputs, menu items */
-  --radius-lg: 14px;  /* cards, panes, popovers */
-  --radius-xl: 16px;  /* dialogs, drawers, command palette */
-  --radius-full: 999px;
-
-  /* Depth — crisp 1px hairline + layered soft shadow underneath.
-     Every elevated surface pairs border: 1px solid var(--border-subtle)
-     with one of these. Shadows are cool-tinted and two-layer:
-     a tight contact shadow + a wide ambient falloff. */
-  --shadow-xs: 0 1px 2px oklch(0.13 0.02 265 / 0.22);
-  --shadow-sm: 0 1px 2px oklch(0.13 0.02 265 / 0.2), 0 2px 8px -2px oklch(0.13 0.02 265 / 0.24);
-  --shadow-md: 0 2px 4px oklch(0.13 0.02 265 / 0.22), 0 10px 28px -6px oklch(0.13 0.02 265 / 0.36);
-  --shadow-lg: 0 4px 8px oklch(0.13 0.02 265 / 0.26), 0 28px 64px -12px oklch(0.13 0.02 265 / 0.5);
-  --shadow-drawer: 0 8px 16px oklch(0.13 0.02 265 / 0.28), 0 32px 80px -8px oklch(0.13 0.02 265 / 0.55);
-
-  /* Glows — hero moments ONLY: empty states, featured cards, command palette */
-  --glow-accent: 0 0 72px -16px color-mix(in oklab, var(--blue-base) 42%, transparent);
-  --glow-secondary: 0 0 72px -16px color-mix(in oklab, var(--cyan-base) 38%, transparent);
-  --glow-ai: 0 0 72px -16px color-mix(in oklab, var(--violet-base) 40%, transparent);
-
-  /* Active rail — left accent bar on active nav / selected items */
-  --rail-active: inset 2px 0 0 0 var(--accent);
-
-  /* Focus ring */
-  --focus-ring: 0 0 0 2px var(--surface-base), 0 0 0 4px var(--border-focus);
-
-  /* Motion — calm, no bounce */
-  --ease-out: cubic-bezier(0.22, 1, 0.36, 1); /* @kind other */
-  --ease-in-out: cubic-bezier(0.65, 0, 0.35, 1); /* @kind other */
-  --duration-fast: 120ms; /* @kind other */
-  --duration-base: 180ms; /* @kind other */
-  --duration-slow: 300ms; /* @kind other */
-  --duration-drawer: 260ms; /* @kind other */
-}
-
-[data-theme="light"] {
-  --shadow-xs: 0 1px 2px oklch(0.3 0.02 255 / 0.07);
-  --shadow-sm: 0 1px 2px oklch(0.3 0.02 255 / 0.06), 0 2px 8px -2px oklch(0.3 0.02 255 / 0.08);
-  --shadow-md: 0 2px 4px oklch(0.3 0.02 255 / 0.06), 0 10px 28px -6px oklch(0.3 0.02 255 / 0.12);
-  --shadow-lg: 0 4px 8px oklch(0.3 0.02 255 / 0.07), 0 28px 64px -12px oklch(0.3 0.02 255 / 0.18);
-  --shadow-drawer: 0 8px 16px oklch(0.3 0.02 255 / 0.08), 0 32px 80px -8px oklch(0.3 0.02 255 / 0.22);
-  --glow-accent: 0 0 72px -16px color-mix(in oklab, var(--blue-deep) 26%, transparent);
-  --glow-secondary: 0 0 72px -16px color-mix(in oklab, var(--cyan-deep) 24%, transparent);
-  --glow-ai: 0 0 72px -16px color-mix(in oklab, var(--violet-deep) 25%, transparent);
-}