Canonical branding guide — internal reference + user-facing asset

[koad]

Context

Vulcan's 2026-04-14 interface package audit (assessments/2026-04-14-interface-package-audit.md) surfaced that style-basic-bitch (Astro-era base theme) is bloated and wrongly positioned. Koad's review reframed the fix: this is not a cleanup task, it's the front end of a product story.

The chain

```
Iris's branding guide (canonical)
→ theme-engine (consumes brand tokens, emits themes)
→ themes (koad:io default + user-built)
→ user apps (drop in, inherit brand)
```

Iris deliverable

Own the canonical branding guide. Brand tokens, voice, visual language.

Two audiences, one artifact:

1. Internal — reference for every koad:io-built surface (sites, dashboards, content, posts).
2. External — a shippable asset users fork to build their own brands on top of the same engine.

Scope

• Brand tokens in a machine-readable form (consumable by theme-engine)
• Voice + visual language as human-readable reference
• Structured so a user can fork and swap without touching the engine

Coordination

• Muse owns theme-engine aesthetic output (parallel issue on koad/muse)
• Vulcan builds the branding guide → theme-engine → themes pipeline (Audit and promote 27 draft interface packages vulcan#74)

Not this issue

• Building the theme-engine itself (Muse + Vulcan)
• Migrating existing sites (Vulcan)