Remove legacy infrastructure, keep only shared rule contracts

Deleted: demo app, designsync/exports bundle system, bible meta-docs,
theme CSS, scaffolds, examples, empty pattern placeholders, go.mod,
CHANGELOG, VERSIONING

Kept: kit/patterns/*/contract.md (all engineering rules),
kit/ai/claude/CLAUDE.template.md, CLAUDE.md, AGENTS.md, README.md

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

AGENTS.md

@@ -1,15 +1,8 @@
-# UI Design Code — Agent Instructions
+# Bible — Instructions for Codex
 
-Read and follow `bible/README.md` as the architecture source of truth.
+This repository is the shared engineering rules library for all projects.
 
-This repository is a submodule-first design kit for Go web projects. Keep shared assets in
-`kit/` generic and reusable; project branding belongs in host repositories.
-
-## Rules
-
-- Architecture and integration contracts live in `bible/` (English only).
-- Significant decisions go to `bible/decisions/10-decisions.md`.
-- Public bundle contracts live in `exports/`; keep them in sync with `kit/`.
-- Prefer updating shared templates/patterns over adding host-specific logic here.
-- Do not broaden the repository scope beyond the currently approved area unless the user
-  explicitly requests it; when in doubt, stay focused on the current scope.
+Rules live in `kit/patterns/` as `contract.md` files. When adding or updating a rule:
+- Find the relevant existing contract and edit it, or create a new `kit/patterns/<topic>/contract.md`.
+- Do not create rules outside `kit/patterns/`.
+- Do not expand scope beyond engineering rules and patterns.