Add designlang public-shell pack; tighten auth capture checks

Ran authenticated extract against coulomb.social; session metadata
matched anonymous Bubble defaults, so treat docs/design-extract as a
public shell baseline (PROVENANCE.md). Capture script now refuses to
overwrite storage-state.json with thin anonymous sessions.

docs/design-extract/README.md

@@ -0,0 +1,63 @@
+# coulomb.social — design system pack
+
+> Built from `https://coulomb.social` on 2026-08-08 by [designlang](https://designlang.app) v12.21.0.
+
+A single, polished bundle of every artifact designlang emits for coulomb.social: tokens, components, a runnable Storybook, a minimal starter, and paste-ready prompts for v0 / Lovable / Cursor / Claude Artifacts.
+
+## At a glance
+
+- **Grade:** B (86/100)
+- **Stack:** unknown · component library: unknown
+- **Type families:** Times New Roman, Helvetica, Inter
+- **Palette:** 6 colors
+- **Spacing base:** 2
+
+## What's in this pack
+
+```
+coulomb-social-design-system/
+├── README.md           ← you are here
+├── LICENSE.txt
+├── tokens/             ← DTCG + Tailwind + CSS vars + Figma vars + motion + theme.js
+├── components/         ← typed React stubs (anatomy.tsx)
+├── storybook/          ← runnable Storybook project
+├── starter/            ← minimal starter app
+├── prompts/            ← v0 · Lovable · Cursor · Claude Artifacts
+└── extras/             ← voice fingerprint + recipe cards
+```
+
+## Install the tokens
+
+### Tailwind
+
+```js
+// tailwind.config.js
+import config from './tokens/tailwind.config.js';
+export default config;
+```
+
+### CSS variables
+
+```html
+<link rel="stylesheet" href="tokens/variables.css">
+```
+
+### Figma
+
+In Figma → Variables panel → import `tokens/figma-variables.json`.
+
+### Storybook
+
+```bash
+cd storybook && npm install && npm run storybook
+```
+
+## Provenance
+
+This pack was extracted from a publicly-accessible URL and represents the *observable design language* of that site at the time of capture. Token values are inferred from computed styles — no source files were accessed. See `LICENSE.txt` for usage guidance.
+
+Re-pack at any time:
+
+```bash
+npx designlang pack coulomb.social
+```