[ksprptr]

Before deploying

• Nothing is required. APP_PRIMARY_COLOR is optional; unset, the app renders exactly as before.
• To rebrand, set it to a single hex (#7c3aed, 7c3aed and #abc all parse) — it is the base
  shade, the rest of the ramp is derived. Anything unparseable falls back to the built-in green.
• The static icon files are gone (app/favicon.ico, app/icon0.svg, app/icon1.png,
  app/apple-icon.png, public/web-app-manifest-*.png) — they are rendered per request now. A
  custom icon can no longer be dropped in as a file.
• Runtime env, so a rebrand needs no rebuild; wired into docker-compose.yml.

What's in it

• One hex drives the whole 50…950 ramp. primary-color.config.ts converts it to OKLCH and
  interpolates every shade: the curve shape (lightness/chroma per step) is averaged over Tailwind's
  17 chromatic palettes, the hue and the saturation come from the hex, and 50/950 keep
  Tailwind's extremes no matter how light or dark the input is.
• layout.tsx puts the --app-primary-* overrides on <html> as an inline style. Unset env
  emits no style attribute at all and globals.css falls back to var(--color-green-*), so the
  default renders byte-identically to before.
• Every green-* class in the UI became primary-*. Red/amber/green stay hard-coded where they
  are semantic — the success toast and the storage quota bar.
• The icons are generated, not files. One renderer draws the cloud-upload glyph on the accent
  color via next/og (no webfont, nothing fetched); app/icon.tsx, app/apple-icon.tsx and
  app/api/icon?size=192|512 for the maskable manifest icons, all force-dynamic.
• proxy.ts had to exempt icon/apple-icon. The generated routes carry no file extension, so
  the matcher's .*\..* escape hatch missed them and the browser's favicon request was being
  bounced to /login.
• theme-color, the manifest and the OG badge follow the same hex — they were pinned to
  #16a34a, Tailwind v3's green, while the UI has been rendering v4's #00a63e since the v4 bump.

Verification

• pnpm build and pnpm lint pass.
• Standalone build run per value — unset and nonsense → theme_color: #00a63e, no style attribute,
  green icon; #7c3aed → #7c3aed, the oklch ramp at hue 293.01, violet icon; e11d48 → likewise.
• /icon, /apple-icon and /api/icon?size=192 all return 200 image/png; the generated badge
  matches the icon1.png it replaces.
• The derived ramp was checked against Tailwind's own violet — same hue, same lightness at 600.