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+// lib/design-catalog.ts — gstack's design anti-pattern vocabulary, typed.
+// Derived in part from pbakaus/impeccable (Apache-2.0), modified. See NOTICE.md.
+//
+// Pure module: no I/O, no imports from scripts/. bin/ and lib/ travel together
+// on every host, scripts/ is never linked, so anything runtime may import this
+// and nothing here may import scripts/.
+//
+//   lib/design-catalog.ts
+//     ├─ scripts/resolvers/constants.ts          AI_SLOP_BLACKLIST: the 11 legacy lines, verbatim, in order
+//     ├─ scripts/resolvers/design.ts             DESIGN_METHODOLOGY cat 9, DESIGN_HARD_RULES,
+//     │                                          DESIGN_REVIEW_LITE, OVERUSED_FONTS, DESIGN_SLOP_BULLETS
+//     ├─ scripts/resolvers/design-checklist.ts   review/design-checklist.md (generated)
+//     ├─ bin/gstack-design-detect.ts             normalizes engine findings by impeccableId
+//     └─ design/src/brief.ts                     MOCKUP_NEVER_NAMES in the image-generation prompt
+//
+// Rule ids. An entry's `impeccableId` is set only when that id exists in
+// test/fixtures/impeccable-antipatterns.json (test-enforced), and rendered
+// prose brackets an id only in that case, so a reader never meets a bracketed
+// id the detector cannot emit. Everything else is a gstack-only tell that the
+// LLM pass judges. The four lists this file replaced (constants.ts, the
+// consultation proposal section, design-html's blacklist, and the review
+// checklist) had drifted apart; they now render from here.
+
+export type SlopCategory =
+  | 'scaffold' | 'surface' | 'type' | 'color' | 'layout'
+  | 'motion' | 'copy' | 'states' | 'imagery' | 'browser-surface';
+export type DetectMethod = 'engine' | 'grep' | 'render' | 'llm';
+export type Confidence = 'HIGH' | 'MEDIUM' | 'LOW';
+export type ReviewTier = 'auto-fix' | 'ask' | 'possible';
+export type Impact = 'high' | 'medium' | 'polish';
+export type FontRole = 'display' | 'body' | 'ui' | 'mono';
+export type Handoff = 'typeset' | 'layout' | 'colorize' | 'harden' | 'clarify' | 'polish' | 'animate' | 'quieter';
+
+/** The `/impeccable <cmd>` commands a deferred finding may hand off to. */
+export const HANDOFF_COMMANDS: readonly Handoff[] = [
+  'typeset', 'layout', 'colorize', 'harden', 'clarify', 'polish', 'animate', 'quieter',
+];
+
+export interface DesignSlopEntry {
+  /** kebab-case; equals impeccableId when the detector knows the rule */
+  id: string;
+  /** set only when the id is in test/fixtures/impeccable-antipatterns.json */
+  impeccableId?: string;
+  /** short label (compact renders, mockup "Never:" line) */
+  name: string;
+  /** the doctrine line, gstack voice (cat 9, checklist, consultation bullets) */
+  prose: string;
+  category: SlopCategory;
+  kind: 'slop' | 'quality';
+  detect: DetectMethod[];
+  /** design-checklist tier */
+  confidence: Confidence;
+  /** review-lite bucket */
+  tier: ReviewTier;
+  /** design-review triage */
+  impact: Impact;
+  /** grep hint rendered in design-checklist.md category 1 */
+  heuristic?: string;
+  /** overused-font names */
+  values?: string[];
+  /** roles the values are banned for; present iff values is */
+  roles?: FontRole[];
+  handoff?: Handoff;
+  source: 'gstack' | 'impeccable' | 'both';
+  /** the 11 originals; AI_SLOP_BLACKLIST derives from these verbatim */
+  legacyBlacklist?: true;
+  /** feeds the design binary's "Never:" prompt line */
+  mockupNever?: true;
+}
+
+/** Training-data defaults: never the display voice on a Persuade or Experience surface. */
+const OVERUSED_DISPLAY = [
+  'Inter', 'Roboto', 'Arial', 'Helvetica', 'Open Sans', 'Lato', 'Montserrat', 'Poppins',
+  'Space Grotesk', 'Space Mono', 'Fraunces', 'Playfair Display', 'Cormorant', 'Lora', 'Crimson',
+  'Newsreader', 'Syne', 'IBM Plex Sans', 'IBM Plex Serif', 'DM Sans', 'DM Serif', 'Outfit',
+  'Plus Jakarta Sans', 'Instrument Sans', 'Geist',
+];
+
+export const DESIGN_SLOP_CATALOG: DesignSlopEntry[] = [
+  // ── The 11 legacy lines. Order and prose are load-bearing: AI_SLOP_BLACKLIST is this list. ──
+  {
+    id: 'ai-color-palette', impeccableId: 'ai-color-palette', name: 'Purple gradient palette',
+    prose: 'Purple/violet/indigo gradient backgrounds or blue-to-purple color schemes',
+    category: 'color', kind: 'slop', detect: ['engine', 'grep', 'llm'], confidence: 'MEDIUM', tier: 'ask', impact: 'medium',
+    heuristic: 'Look for `linear-gradient` with values in the `#6366f1` to `#8b5cf6` range, or CSS custom properties resolving to purple/violet.',
+    handoff: 'colorize', source: 'both', legacyBlacklist: true,
+  },
+  {
+    id: 'feature-grid-3col', name: 'The 3-column feature grid',
+    prose: '**The 3-column feature grid:** icon-in-colored-circle + bold title + 2-line description, repeated 3x symmetrically. THE most recognizable AI layout.',
+    category: 'scaffold', kind: 'slop', detect: ['grep', 'llm'], confidence: 'LOW', tier: 'ask', impact: 'medium',
+    heuristic: 'Look for a grid/flex container with exactly 3 children that each contain a circular element + heading + paragraph.',
+    handoff: 'layout', source: 'gstack', legacyBlacklist: true,
+  },
+  {
+    id: 'icon-circle-decoration', name: 'Icons in colored circles',
+    prose: 'Icons in colored circles as section decoration (SaaS starter template look)',
+    category: 'scaffold', kind: 'slop', detect: ['grep', 'llm'], confidence: 'LOW', tier: 'ask', impact: 'medium',
+    heuristic: 'Look for elements with `border-radius: 50%` + a background color used as decorative containers for icons.',
+    handoff: 'quieter', source: 'gstack', legacyBlacklist: true,
+  },
+  {
+    id: 'centered-everything', name: 'Centered everything',
+    prose: 'Centered everything (`text-align: center` on all headings, descriptions, cards)',
+    category: 'layout', kind: 'slop', detect: ['grep', 'llm'], confidence: 'HIGH', tier: 'ask', impact: 'medium',
+    heuristic: 'Grep for `text-align: center` density: if more than 60% of text containers center, flag it.',
+    handoff: 'layout', source: 'gstack', legacyBlacklist: true,
+  },
+  {
+    id: 'uniform-radius', name: 'Uniform bubbly border-radius',
+    prose: 'Uniform bubbly border-radius on every element (same large radius on everything)',
+    category: 'surface', kind: 'slop', detect: ['grep', 'llm'], confidence: 'MEDIUM', tier: 'ask', impact: 'medium',
+    heuristic: 'Aggregate `border-radius` values: if more than 80% share one value of 16px or more, flag it. Pill radius on everything is the extreme case.',
+    handoff: 'polish', source: 'gstack', legacyBlacklist: true,
+  },
+  {
+    id: 'decorative-blobs', name: 'Decorative blobs and dividers',
+    prose: 'Decorative blobs, floating circles, wavy SVG dividers (if a section feels empty, it needs better content, not decoration)',
+    category: 'imagery', kind: 'slop', detect: ['llm'], confidence: 'LOW', tier: 'ask', impact: 'medium',
+    handoff: 'quieter', source: 'gstack', legacyBlacklist: true,
+  },
+  {
+    id: 'emoji-decoration', name: 'Emoji as design elements',
+    prose: 'Emoji as design elements (rockets in headings, emoji as bullet points)',
+    category: 'imagery', kind: 'slop', detect: ['grep', 'llm'], confidence: 'MEDIUM', tier: 'ask', impact: 'medium',
+    heuristic: 'Grep headings, list items, and buttons for emoji code points used as icons or bullets.',
+    handoff: 'polish', source: 'gstack', legacyBlacklist: true,
+  },
+  {
+    id: 'side-tab', impeccableId: 'side-tab', name: 'Colored left-border on cards',
+    prose: 'Colored left-border on cards (`border-left: 3px solid <accent>`)',
+    category: 'surface', kind: 'slop', detect: ['engine', 'grep'], confidence: 'HIGH', tier: 'ask', impact: 'medium',
+    heuristic: 'Grep for `border-left: <n>px solid` on card, callout, or list-item selectors.',
+    handoff: 'polish', source: 'both', legacyBlacklist: true,
+  },
+  {
+    id: 'generic-hero-copy', name: 'Generic hero copy',
+    prose: 'Generic hero copy ("Welcome to [X]", "Unlock the power of...", "Your all-in-one solution for...")',
+    category: 'copy', kind: 'slop', detect: ['grep', 'llm'], confidence: 'MEDIUM', tier: 'ask', impact: 'medium',
+    heuristic: 'Grep HTML/JSX content for "Welcome to", "Unlock the power of", "Your all-in-one solution", "Revolutionize your", "Streamline your workflow".',
+    handoff: 'clarify', source: 'gstack', legacyBlacklist: true,
+  },
+  {
+    id: 'cookie-cutter-rhythm', name: 'Cookie-cutter section rhythm',
+    prose: 'Cookie-cutter section rhythm (hero → 3 features → testimonials → pricing → CTA, every section same height)',
+    category: 'scaffold', kind: 'slop', detect: ['llm'], confidence: 'LOW', tier: 'ask', impact: 'medium',
+    handoff: 'layout', source: 'gstack', legacyBlacklist: true,
+  },
+  {
+    id: 'system-font-primary', name: 'system-ui as the primary face',
+    prose: 'system-ui or `-apple-system` as the PRIMARY display/body font — the "I gave up on typography" signal. Pick a real typeface.',
+    category: 'type', kind: 'slop', detect: ['grep'], confidence: 'HIGH', tier: 'ask', impact: 'medium',
+    heuristic: 'Grep `font-family` on body, headings, and base styles for `system-ui` or `-apple-system` as the first face in the stack.',
+    handoff: 'typeset', source: 'gstack', legacyBlacklist: true,
+  },
+
+  // ── Slop the detector knows (ids from the registry fixture). ──
+  {
+    id: 'border-accent-on-rounded', impeccableId: 'border-accent-on-rounded', name: 'Border accent on a rounded card',
+    prose: 'A colored edge on a rounded card: the side-tab in a costume. Signal state with a background tint, an icon, or a label.',
+    category: 'surface', kind: 'slop', detect: ['engine'], confidence: 'MEDIUM', tier: 'ask', impact: 'medium',
+    handoff: 'polish', source: 'impeccable',
+  },
+  {
+    id: 'overused-font', impeccableId: 'overused-font', name: 'Overused display font',
+    prose: 'A training-data default as the display voice means you stopped looking. As body or UI on an Operate or Read surface, several of these are fine. Say which and why.',
+    category: 'type', kind: 'slop', detect: ['engine', 'grep', 'llm'], confidence: 'MEDIUM', tier: 'ask', impact: 'medium',
+    heuristic: 'Grep `font-family` for a listed face as the first face on display selectors (h1, h2, .hero, .display).',
+    values: OVERUSED_DISPLAY, roles: ['display'],
+    handoff: 'typeset', source: 'both',
+  },
+  {
+    id: 'flat-type-hierarchy', impeccableId: 'flat-type-hierarchy', name: 'Flat type hierarchy',
+    prose: 'Headings within a step of body size. Pick a scale and let the levels differ by more than a weight.',
+    category: 'type', kind: 'slop', detect: ['engine', 'llm'], confidence: 'MEDIUM', tier: 'ask', impact: 'medium',
+    handoff: 'typeset', source: 'impeccable',
+  },
+  {
+    id: 'gradient-text', impeccableId: 'gradient-text', name: 'Gradient text',
+    prose: 'Emphasis is weight or size. Gradient text is emphasis in a costume.',
+    category: 'color', kind: 'slop', detect: ['engine', 'grep'], confidence: 'HIGH', tier: 'ask', impact: 'medium',
+    heuristic: 'Grep for `background-clip: text` next to a gradient background.',
+    handoff: 'colorize', source: 'impeccable',
+  },
+  {
+    id: 'cream-palette', impeccableId: 'cream-palette', name: 'Cream default palette',
+    prose: 'Cream ground, serif display, terracotta accent: look number one. Fine when the brief asked for it; a default when it did not.',
+    category: 'color', kind: 'slop', detect: ['engine', 'llm'], confidence: 'MEDIUM', tier: 'ask', impact: 'medium',
+    handoff: 'colorize', source: 'impeccable',
+  },
+  {
+    id: 'nested-cards', impeccableId: 'nested-cards', name: 'Nested cards',
+    prose: 'A card inside a card is always wrong. Cards are the lazy container; nesting them is the lazy container squared.',
+    category: 'scaffold', kind: 'slop', detect: ['engine', 'llm'], confidence: 'MEDIUM', tier: 'ask', impact: 'medium',
+    handoff: 'layout', source: 'impeccable',
+  },
+  {
+    id: 'monotonous-spacing', impeccableId: 'monotonous-spacing', name: 'Monotonous spacing',
+    prose: 'One gap value between everything. Rhythm needs a large step and a small step, not a single beat.',
+    category: 'layout', kind: 'slop', detect: ['engine', 'llm'], confidence: 'MEDIUM', tier: 'ask', impact: 'polish',
+    handoff: 'layout', source: 'impeccable',
+  },
+  {
+    id: 'bounce-easing', impeccableId: 'bounce-easing', name: 'Bounce easing',
+    prose: 'Overshoot and bounce curves on UI motion. Exponential ease-out from an already-visible default.',
+    category: 'motion', kind: 'slop', detect: ['engine', 'grep'], confidence: 'HIGH', tier: 'ask', impact: 'polish',
+    heuristic: 'Grep transitions and keyframes for cubic-bezier curves with a control point past 1, or `bounce` in animation names.',
+    handoff: 'animate', source: 'impeccable',
+  },
+  {
+    id: 'pulsing-dot', impeccableId: 'pulsing-dot', name: 'Pulsing status dot',
+    prose: 'A small circle pulsing forever next to "Live" or "Online". Motion that says nothing new after the first loop.',
+    category: 'motion', kind: 'slop', detect: ['engine', 'grep'], confidence: 'MEDIUM', tier: 'ask', impact: 'polish',
+    heuristic: 'Grep for infinite keyframe animations on small round elements.',
+    handoff: 'animate', source: 'impeccable',
+  },
+  {
+    id: 'blinking-cursor', impeccableId: 'blinking-cursor', name: 'Blinking cursor effect',
+    prose: 'A fake terminal cursor blinking in marketing copy. Theater, not interface.',
+    category: 'motion', kind: 'slop', detect: ['engine'], confidence: 'MEDIUM', tier: 'ask', impact: 'polish',
+    handoff: 'animate', source: 'impeccable',
+  },
+  {
+    id: 'shape-assembled-illustration', impeccableId: 'shape-assembled-illustration', name: 'Shape-assembled illustration',
+    prose: 'An illustration built from CSS shapes standing in for an asset. Produce the asset or ship nothing.',
+    category: 'imagery', kind: 'slop', detect: ['engine', 'llm'], confidence: 'MEDIUM', tier: 'ask', impact: 'medium',
+    handoff: 'quieter', source: 'impeccable',
+  },
+  {
+    id: 'dark-glow', impeccableId: 'dark-glow', name: 'Dark-mode glow',
+    prose: 'Glowing edges on dark surfaces: look number two. Depth has an offset; a zero-offset colored halo is decoration.',
+    category: 'surface', kind: 'slop', detect: ['engine', 'grep'], confidence: 'HIGH', tier: 'ask', impact: 'medium',
+    heuristic: 'Grep `box-shadow` for a zero x/y offset with a large blur and a saturated color.',
+    handoff: 'colorize', source: 'impeccable',
+  },
+  {
+    id: 'radial-halo', impeccableId: 'radial-halo', name: 'Radial halo',
+    prose: 'A radial gradient halo behind the hero content. Look number two again.',
+    category: 'surface', kind: 'slop', detect: ['engine'], confidence: 'MEDIUM', tier: 'ask', impact: 'medium',
+    handoff: 'quieter', source: 'impeccable',
+  },
+  {
+    id: 'radial-spotlight-glow', impeccableId: 'radial-spotlight-glow', name: 'Radial spotlight glow',
+    prose: 'A spotlight glow washing the top of the page. Same family as the halo.',
+    category: 'surface', kind: 'slop', detect: ['engine'], confidence: 'MEDIUM', tier: 'ask', impact: 'medium',
+    handoff: 'quieter', source: 'impeccable',
+  },
+  {
+    id: 'marquee', impeccableId: 'marquee', name: 'Logo marquee',
+    prose: 'An infinitely scrolling logo strip. If the logos matter, show them still; if they do not, cut them.',
+    category: 'motion', kind: 'slop', detect: ['engine', 'llm'], confidence: 'MEDIUM', tier: 'ask', impact: 'medium',
+    handoff: 'animate', source: 'impeccable',
+  },
+  {
+    id: 'icon-tile-stack', impeccableId: 'icon-tile-stack', name: 'Icon tile above every heading',
+    prose: 'The rounded-square icon above every heading. Try side by side, or drop the container.',
+    category: 'scaffold', kind: 'slop', detect: ['engine', 'llm'], confidence: 'MEDIUM', tier: 'ask', impact: 'medium',
+    handoff: 'layout', source: 'impeccable',
+  },
+  {
+    id: 'italic-serif-display', impeccableId: 'italic-serif-display', name: 'Italic serif display',
+    prose: 'Look three: the italic display serif reaching for editorial credibility. Earn it with the content or set the display upright.',
+    category: 'type', kind: 'slop', detect: ['engine', 'llm'], confidence: 'MEDIUM', tier: 'ask', impact: 'medium',
+    handoff: 'typeset', source: 'impeccable',
+  },
+  {
+    id: 'hero-eyebrow-chip', impeccableId: 'hero-eyebrow-chip', name: 'Hero eyebrow chip',
+    prose: 'A pill-shaped label floating above the hero headline. The headline carries its own weight; cut the chip.',
+    category: 'scaffold', kind: 'slop', detect: ['engine', 'llm'], confidence: 'MEDIUM', tier: 'ask', impact: 'medium',
+    handoff: 'quieter', source: 'impeccable',
+  },
+  {
+    id: 'kicker-above-heading', impeccableId: 'kicker-above-heading', name: 'Kicker above heading',
+    prose: 'A kicker above a heading is the strongest default there is: the heading carries its own weight, so delete the label. If the user wants it anyway, comply and say the tradeoff once.',
+    category: 'scaffold', kind: 'slop', detect: ['engine', 'grep', 'llm'], confidence: 'MEDIUM', tier: 'ask', impact: 'medium',
+    heuristic: 'Look for a short uppercase, tracked element immediately before an h1 or h2.',
+    handoff: 'layout', source: 'impeccable',
+  },
+  {
+    id: 'numbered-section-labels', impeccableId: 'numbered-section-labels', name: 'Numbered section labels',
+    prose: '01 / 02 / 03 over sections, unless the sequence is information the reader needs.',
+    category: 'scaffold', kind: 'slop', detect: ['engine', 'llm'], confidence: 'MEDIUM', tier: 'ask', impact: 'polish',
+    handoff: 'layout', source: 'impeccable',
+  },
+  {
+    id: 'em-dash-overuse', impeccableId: 'em-dash-overuse', name: 'Em-dash overuse',
+    prose: 'Em dashes in every other sentence. Advisory: a tell of generated copy, never a blocker on its own.',
+    category: 'copy', kind: 'slop', detect: ['engine'], confidence: 'LOW', tier: 'possible', impact: 'polish',
+    handoff: 'clarify', source: 'impeccable',
+  },
+  {
+    id: 'marketing-buzzword', impeccableId: 'marketing-buzzword', name: 'Marketing buzzwords',
+    prose: '"Seamless", "effortless", "supercharge", "streamline": words that describe nothing. Say what the product does.',
+    category: 'copy', kind: 'slop', detect: ['engine', 'grep'], confidence: 'MEDIUM', tier: 'ask', impact: 'medium',
+    heuristic: 'Grep visible copy for seamless, effortless, supercharge, streamline, revolutionize, unlock, empower, elevate.',
+    handoff: 'clarify', source: 'impeccable',
+  },
+  {
+    id: 'aphoristic-cadence', impeccableId: 'aphoristic-cadence', name: 'Aphoristic cadence',
+    prose: 'Short. Punchy. Fragments. Every sentence a slogan. Write like a person explaining something.',
+    category: 'copy', kind: 'slop', detect: ['engine', 'llm'], confidence: 'MEDIUM', tier: 'ask', impact: 'medium',
+    handoff: 'clarify', source: 'impeccable',
+  },
+  {
+    id: 'oversized-h1', impeccableId: 'oversized-h1', name: 'Oversized h1',
+    prose: 'Display type past 6rem on a page that is not a poster. Size is not hierarchy.',
+    category: 'type', kind: 'slop', detect: ['engine', 'grep'], confidence: 'HIGH', tier: 'ask', impact: 'medium',
+    heuristic: 'Grep h1 and display selectors for font-size above 6rem or 96px.',
+    handoff: 'typeset', source: 'impeccable',
+  },
+  {
+    id: 'extreme-negative-tracking', impeccableId: 'extreme-negative-tracking', name: 'Extreme negative tracking',
+    prose: 'Letter-spacing below -0.04em on display type. Tight tracking is a taste; crushed tracking is a tell.',
+    category: 'type', kind: 'slop', detect: ['engine', 'grep'], confidence: 'HIGH', tier: 'ask', impact: 'polish',
+    heuristic: 'Grep `letter-spacing` for values below -0.04em.',
+    handoff: 'typeset', source: 'impeccable',
+  },
+  {
+    id: 'gpt-thin-border-wide-shadow', impeccableId: 'gpt-thin-border-wide-shadow', name: 'Thin border plus wide shadow',
+    prose: 'A hairline border and a wide soft shadow on the same card. Pick one way to lift the surface.',
+    category: 'surface', kind: 'slop', detect: ['engine'], confidence: 'MEDIUM', tier: 'ask', impact: 'polish',
+    handoff: 'polish', source: 'impeccable',
+  },
+  {
+    id: 'repeating-stripes-gradient', impeccableId: 'repeating-stripes-gradient', name: 'Repeating stripes gradient',
+    prose: 'Diagonal stripe gradients as background texture. Texture from the brand or none.',
+    category: 'surface', kind: 'slop', detect: ['engine'], confidence: 'MEDIUM', tier: 'ask', impact: 'polish',
+    handoff: 'quieter', source: 'impeccable',
+  },
+  {
+    id: 'codex-grid-background', impeccableId: 'codex-grid-background', name: 'Grid-paper background',
+    prose: 'A faint grid behind the hero. The blueprint look every generated dev tool ships.',
+    category: 'surface', kind: 'slop', detect: ['engine'], confidence: 'MEDIUM', tier: 'ask', impact: 'polish',
+    handoff: 'quieter', source: 'impeccable',
+  },
+  {
+    id: 'theater-slop-phrase', impeccableId: 'theater-slop-phrase', name: 'Theater phrases',
+    prose: '"Built for the way you work", "Designed for teams like yours", "Meet your new...": phrases that perform a launch instead of describing one.',
+    category: 'copy', kind: 'slop', detect: ['engine', 'grep'], confidence: 'MEDIUM', tier: 'ask', impact: 'medium',
+    heuristic: 'Grep copy for "built for", "designed for", "meet your new", "ship faster", "the future of".',
+    handoff: 'clarify', source: 'impeccable',
+  },
+  {
+    id: 'image-hover-transform', impeccableId: 'image-hover-transform', name: 'Image hover zoom',
+    prose: 'Scaling an image on hover. Motion with no information in it.',
+    category: 'motion', kind: 'slop', detect: ['engine', 'grep'], confidence: 'MEDIUM', tier: 'ask', impact: 'polish',
+    heuristic: 'Grep `:hover` rules on images for `transform: scale`.',
+    handoff: 'animate', source: 'impeccable',
+  },
+
+  // ── gstack-only slop tells: the LLM pass judges these; no detector id, so no brackets. ──
+  {
+    id: 'gradient-cta', name: 'Gradient CTA button',
+    prose: 'Gradient buttons as the primary call to action. One solid color the palette owns.',
+    category: 'color', kind: 'slop', detect: ['grep', 'llm'], confidence: 'MEDIUM', tier: 'ask', impact: 'medium',
+    heuristic: 'Grep button and CTA selectors for gradient backgrounds.',
+    handoff: 'colorize', source: 'gstack',
+  },
+  {
+    id: 'stock-photo-hero', name: 'Stock-photo hero',
+    prose: 'A generic stock-photo hero, or a gray placeholder div standing in for one. Show the product or show nothing.',
+    category: 'imagery', kind: 'slop', detect: ['llm'], confidence: 'LOW', tier: 'ask', impact: 'medium',
+    handoff: 'quieter', source: 'gstack',
+  },
+  {
+    id: 'card-default-component', name: 'Cards as the default component',
+    prose: 'Rounded cards with drop shadows as the container for everything. App UI made of stacked cards is not layout.',
+    category: 'scaffold', kind: 'slop', detect: ['llm'], confidence: 'LOW', tier: 'ask', impact: 'medium',
+    handoff: 'layout', source: 'gstack',
+  },
+  {
+    id: 'generic-testimonials', name: 'Generic testimonial section',
+    prose: 'A testimonial row with avatars, five stars, and quotes nobody said. Real names with real claims, or cut it.',
+    category: 'scaffold', kind: 'slop', detect: ['llm'], confidence: 'LOW', tier: 'ask', impact: 'medium',
+    handoff: 'clarify', source: 'gstack',
+  },
+  {
+    id: 'split-hero-template', name: 'Left-text right-image hero',
+    prose: 'The cookie-cutter hero: headline left, screenshot right, two buttons. The first template every generator reaches for.',
+    category: 'scaffold', kind: 'slop', detect: ['llm'], confidence: 'LOW', tier: 'ask', impact: 'medium',
+    handoff: 'layout', source: 'gstack',
+  },
+  {
+    id: 'generic-cta-copy', name: 'Generic CTA labels',
+    prose: '"Get Started" and "Learn More" as the only calls to action. Name the outcome the click buys.',
+    category: 'copy', kind: 'slop', detect: ['grep', 'llm'], confidence: 'MEDIUM', tier: 'ask', impact: 'medium',
+    heuristic: 'Grep buttons and links for "Get Started" and "Learn More" with no more specific CTA on the page.',
+    handoff: 'clarify', source: 'gstack',
+  },
+  {
+    id: 'hero-metrics', name: 'Hero metric template',
+    prose: 'Three big numbers with tiny labels under the hero ("10k+ users", "99.9%"). The template counts, not the product.',
+    category: 'scaffold', kind: 'slop', detect: ['llm'], confidence: 'LOW', tier: 'ask', impact: 'medium',
+    handoff: 'clarify', source: 'gstack',
+  },
+  {
+    id: 'identical-cards', name: 'Identical card grids',
+    prose: 'A grid of cards with the same shape, the same icon slot, the same two lines. Content of unequal weight given equal boxes.',
+    category: 'scaffold', kind: 'slop', detect: ['llm'], confidence: 'LOW', tier: 'ask', impact: 'medium',
+    handoff: 'layout', source: 'gstack',
+  },
+  {
+    id: 'glassmorphism', name: 'Glassmorphism',
+    prose: 'Frosted-glass panels with blurred backdrops as the default surface. One translucent layer where it explains depth, not everywhere.',
+    category: 'surface', kind: 'slop', detect: ['grep', 'llm'], confidence: 'MEDIUM', tier: 'ask', impact: 'medium',
+    heuristic: 'Grep for `backdrop-filter: blur` on more than one container.',
+    handoff: 'quieter', source: 'gstack',
+  },
+  {
+    id: 'hand-drawn-svg', name: 'Hand-drawn SVG illustration',
+    prose: 'Generated SVG doodles and mascots in place of art direction. Commission or license an asset, or ship none.',
+    category: 'imagery', kind: 'slop', detect: ['llm'], confidence: 'LOW', tier: 'ask', impact: 'medium',
+    handoff: 'quieter', source: 'gstack',
+  },
+  {
+    id: 'modal-by-default', name: 'Modal by default',
+    prose: 'Every secondary action in a modal. Inline, a side panel, or a new page usually costs the user less.',
+    category: 'states', kind: 'slop', detect: ['llm'], confidence: 'LOW', tier: 'ask', impact: 'medium',
+    handoff: 'harden', source: 'gstack',
+  },
+  {
+    id: 'monospace-costume', name: 'Monospace as costume',
+    prose: 'Monospace on labels and body copy to look technical. Mono is for code and data columns.',
+    category: 'type', kind: 'slop', detect: ['grep', 'llm'], confidence: 'MEDIUM', tier: 'ask', impact: 'polish',
+    heuristic: 'Grep `font-family` for a monospace stack on non-code, non-tabular selectors.',
+    handoff: 'typeset', source: 'gstack',
+  },
+  {
+    id: 'content-stand-ins', name: 'Content stand-ins',
+    prose: 'Sparklines, progress rings, and fake avatars filling space where content should be. Real data or an honest empty state.',
+    category: 'imagery', kind: 'slop', detect: ['llm'], confidence: 'LOW', tier: 'ask', impact: 'medium',
+    handoff: 'harden', source: 'gstack',
+  },
+  {
+    id: 'mode-by-category', name: 'Mode picked by category',
+    prose: 'Dark because it is a dev tool, light because it is health. Light or dark comes from the use scene: who, where, under what light.',
+    category: 'color', kind: 'slop', detect: ['llm'], confidence: 'LOW', tier: 'ask', impact: 'medium',
+    handoff: 'colorize', source: 'gstack',
+  },
+  {
+    id: 'unthemed-browser-surfaces', name: 'Unthemed browser surfaces',
+    prose: 'Selection color, caret, scrollbars, focus rings, underline offset, tabular numerals left at browser defaults. Theme them from the palette.',
+    category: 'browser-surface', kind: 'slop', detect: ['grep', 'llm'], confidence: 'MEDIUM', tier: 'ask', impact: 'polish',
+    heuristic: 'Grep for `::selection`, `caret-color`, `accent-color`, `scrollbar-color`, `text-underline-offset`, `font-variant-numeric`: none present means none themed.',
+    handoff: 'polish', source: 'gstack',
+  },
+  {
+    id: 'missing-states', name: 'Missing states',
+    prose: 'Only the happy path is designed. Empty, loading, error, and long-content states are part of the component.',
+    category: 'states', kind: 'slop', detect: ['llm'], confidence: 'LOW', tier: 'ask', impact: 'high',
+    handoff: 'harden', source: 'gstack',
+  },
+
+  // ── Quality rules the detector knows. ──
+  {
+    id: 'organic-clip-path', impeccableId: 'organic-clip-path', name: 'Organic clip-path',
+    prose: 'A polygon clip-path approximating a photo edge or a blob. An asset with its own edge, or a rectangle.',
+    category: 'imagery', kind: 'quality', detect: ['engine'], confidence: 'MEDIUM', tier: 'ask', impact: 'medium',
+    handoff: 'quieter', source: 'impeccable',
+  },
+  {
+    id: 'buried-raster', impeccableId: 'buried-raster', name: 'Buried raster',
+    prose: 'A photo under a near-opaque wash. If the image cannot be seen, it is not doing anything.',
+    category: 'imagery', kind: 'quality', detect: ['engine'], confidence: 'MEDIUM', tier: 'ask', impact: 'medium',
+    handoff: 'quieter', source: 'impeccable',
+  },
+  {
+    id: 'broken-image', impeccableId: 'broken-image', name: 'Broken image',
+    prose: 'An image that fails to load. Nothing on the page is more visible.',
+    category: 'imagery', kind: 'quality', detect: ['engine', 'render'], confidence: 'HIGH', tier: 'ask', impact: 'high',
+    handoff: 'harden', source: 'impeccable',
+  },
+  {
+    id: 'script-error', impeccableId: 'script-error', name: 'Script error',
+    prose: 'A JavaScript error in the console on load. The page is not finished.',
+    category: 'states', kind: 'quality', detect: ['engine', 'render'], confidence: 'HIGH', tier: 'ask', impact: 'high',
+    handoff: 'harden', source: 'impeccable',
+  },
+  {
+    id: 'content-hidden-at-rest', impeccableId: 'content-hidden-at-rest', name: 'Content hidden at rest',
+    prose: 'Content at opacity 0 waiting for a scroll animation that may never fire. Content is visible by default.',
+    category: 'motion', kind: 'quality', detect: ['engine', 'render'], confidence: 'HIGH', tier: 'ask', impact: 'high',
+    handoff: 'animate', source: 'impeccable',
+  },
+  {
+    id: 'edge-flush-cards', impeccableId: 'edge-flush-cards', name: 'Edge-flush cards',
+    prose: 'Cards touching the viewport edge. Give the layout a gutter.',
+    category: 'layout', kind: 'quality', detect: ['engine', 'render'], confidence: 'MEDIUM', tier: 'ask', impact: 'medium',
+    handoff: 'layout', source: 'impeccable',
+  },
+  {
+    id: 'text-occlusion', impeccableId: 'text-occlusion', name: 'Text occlusion',
+    prose: 'Text covered by another element. Overlap is a bug until it is a choice.',
+    category: 'layout', kind: 'quality', detect: ['engine', 'render'], confidence: 'HIGH', tier: 'ask', impact: 'high',
+    handoff: 'harden', source: 'impeccable',
+  },
+  {
+    id: 'first-viewport-column-overflow', impeccableId: 'first-viewport-column-overflow', name: 'First-viewport overflow',
+    prose: 'A column wider than the first viewport. Horizontal scroll on arrival.',
+    category: 'layout', kind: 'quality', detect: ['engine', 'render'], confidence: 'HIGH', tier: 'ask', impact: 'high',
+    handoff: 'layout', source: 'impeccable',
+  },
+  {
+    id: 'gray-on-color', impeccableId: 'gray-on-color', name: 'Gray text on a colored surface',
+    prose: 'Secondary text on a colored surface is tinted from that hue. Never gray.',
+    category: 'color', kind: 'quality', detect: ['engine'], confidence: 'MEDIUM', tier: 'ask', impact: 'medium',
+    handoff: 'colorize', source: 'impeccable',
+  },
+  {
+    id: 'low-contrast', impeccableId: 'low-contrast', name: 'Low contrast text',
+    prose: 'Text below WCAG AA contrast (4.5:1 body, 3:1 large). Fix the pair, not the opacity.',
+    category: 'color', kind: 'quality', detect: ['engine', 'render'], confidence: 'HIGH', tier: 'ask', impact: 'high',
+    handoff: 'colorize', source: 'impeccable',
+  },
+  {
+    id: 'layout-transition', impeccableId: 'layout-transition', name: 'Layout-property transition',
+    prose: '`transition: all`, or transitions on width, height, top, left. Animate transform and opacity.',
+    category: 'motion', kind: 'quality', detect: ['engine', 'grep'], confidence: 'HIGH', tier: 'auto-fix', impact: 'polish',
+    heuristic: 'Grep `transition` for `all` or layout properties.',
+    handoff: 'animate', source: 'impeccable',
+  },
+  {
+    id: 'line-length', impeccableId: 'line-length', name: 'Line length',
+    prose: 'Body measure outside 45 to 75 characters. Set a max-width on the text column.',
+    category: 'type', kind: 'quality', detect: ['engine', 'grep'], confidence: 'MEDIUM', tier: 'ask', impact: 'medium',
+    heuristic: 'Check for `max-width` on body text wrappers.',
+    handoff: 'typeset', source: 'impeccable',
+  },
+  {
+    id: 'cramped-padding', impeccableId: 'cramped-padding', name: 'Cramped padding',
+    prose: 'Padding under 8px on text containers. Text needs room to breathe.',
+    category: 'layout', kind: 'quality', detect: ['engine'], confidence: 'MEDIUM', tier: 'ask', impact: 'medium',
+    handoff: 'layout', source: 'impeccable',
+  },
+  {
+    id: 'body-text-viewport-edge', impeccableId: 'body-text-viewport-edge', name: 'Body text at the viewport edge',
+    prose: 'Body text within a few pixels of the viewport edge on small screens.',
+    category: 'layout', kind: 'quality', detect: ['engine', 'render'], confidence: 'MEDIUM', tier: 'ask', impact: 'medium',
+    handoff: 'layout', source: 'impeccable',
+  },
+  {
+    id: 'tight-leading', impeccableId: 'tight-leading', name: 'Tight leading',
+    prose: 'Body line-height under 1.4. Display type can run tight; paragraphs cannot.',
+    category: 'type', kind: 'quality', detect: ['engine', 'grep'], confidence: 'HIGH', tier: 'ask', impact: 'medium',
+    heuristic: 'Grep body and paragraph `line-height` for values below 1.4.',
+    handoff: 'typeset', source: 'impeccable',
+  },
+  {
+    id: 'skipped-heading', impeccableId: 'skipped-heading', name: 'Skipped heading level',
+    prose: 'h1 followed by h3 with no h2. Screen readers walk the hierarchy.',
+    category: 'type', kind: 'quality', detect: ['engine', 'grep'], confidence: 'HIGH', tier: 'ask', impact: 'medium',
+    heuristic: 'Check HTML/JSX for heading tags that skip a level within a file or component.',
+    handoff: 'typeset', source: 'impeccable',
+  },
+  {
+    id: 'heading-rhythm', impeccableId: 'heading-rhythm', name: 'Heading rhythm',
+    prose: 'More space above a heading than below it. Read the computed values.',
+    category: 'type', kind: 'quality', detect: ['engine'], confidence: 'MEDIUM', tier: 'ask', impact: 'polish',
+    handoff: 'typeset', source: 'impeccable',
+  },
+  {
+    id: 'justified-text', impeccableId: 'justified-text', name: 'Justified text',
+    prose: 'Justified body text on the web leaves rivers. Left-align.',
+    category: 'type', kind: 'quality', detect: ['engine', 'grep'], confidence: 'HIGH', tier: 'auto-fix', impact: 'polish',
+    heuristic: 'Grep for `text-align: justify`.',
+    handoff: 'typeset', source: 'impeccable',
+  },
+  {
+    id: 'tiny-text', impeccableId: 'tiny-text', name: 'Tiny text',
+    prose: 'Body text under 16px. Bump to 16px.',
+    category: 'type', kind: 'quality', detect: ['engine', 'grep'], confidence: 'HIGH', tier: 'auto-fix', impact: 'medium',
+    heuristic: 'Grep `font-size` on body, p, and base styles for values under 16px (1rem at a 16px base).',
+    handoff: 'typeset', source: 'impeccable',
+  },
+  {
+    id: 'undersized-ui-text', impeccableId: 'undersized-ui-text', name: 'Undersized UI text',
+    prose: 'Labels and controls under 12px. Nobody reads 10px.',
+    category: 'type', kind: 'quality', detect: ['engine'], confidence: 'HIGH', tier: 'ask', impact: 'medium',
+    handoff: 'typeset', source: 'impeccable',
+  },
+  {
+    id: 'all-caps-body', impeccableId: 'all-caps-body', name: 'All-caps body text',
+    prose: 'Uppercase paragraphs. Caps are for short labels.',
+    category: 'type', kind: 'quality', detect: ['engine', 'grep'], confidence: 'HIGH', tier: 'auto-fix', impact: 'medium',
+    heuristic: 'Grep `text-transform: uppercase` on body and paragraph selectors.',
+    handoff: 'typeset', source: 'impeccable',
+  },
+  {
+    id: 'wide-tracking', impeccableId: 'wide-tracking', name: 'Wide tracking on body',
+    prose: 'Letter-spacing above 0.05em on body text. Tracked type is for small-caps labels.',
+    category: 'type', kind: 'quality', detect: ['engine', 'grep'], confidence: 'MEDIUM', tier: 'ask', impact: 'polish',
+    heuristic: 'Grep body `letter-spacing` for values above 0.05em.',
+    handoff: 'typeset', source: 'impeccable',
+  },
+  {
+    id: 'text-overflow', impeccableId: 'text-overflow', name: 'Text overflow',
+    prose: 'Text spilling out of its container. Long content is the normal case.',
+    category: 'states', kind: 'quality', detect: ['engine', 'render'], confidence: 'HIGH', tier: 'ask', impact: 'high',
+    handoff: 'harden', source: 'impeccable',
+  },
+  {
+    id: 'repeated-container-text', impeccableId: 'repeated-container-text', name: 'Repeated container text',
+    prose: 'The same text repeated across sibling containers. Placeholder content that shipped.',
+    category: 'copy', kind: 'quality', detect: ['engine'], confidence: 'MEDIUM', tier: 'ask', impact: 'medium',
+    handoff: 'clarify', source: 'impeccable',
+  },
+  {
+    id: 'clipped-overflow-container', impeccableId: 'clipped-overflow-container', name: 'Clipped overflow',
+    prose: 'A container clipping its own content with overflow hidden. Something is cut off.',
+    category: 'states', kind: 'quality', detect: ['engine', 'render'], confidence: 'MEDIUM', tier: 'ask', impact: 'medium',
+    handoff: 'harden', source: 'impeccable',
+  },
+  {
+    id: 'design-system-font', impeccableId: 'design-system-font', name: 'Off-system font',
+    prose: 'A face DESIGN.md tokens do not name. Add the token or use one that exists.',
+    category: 'type', kind: 'quality', detect: ['engine'], confidence: 'MEDIUM', tier: 'ask', impact: 'medium',
+    handoff: 'polish', source: 'impeccable',
+  },
+  {
+    id: 'design-system-color', impeccableId: 'design-system-color', name: 'Off-system color',
+    prose: 'A color DESIGN.md tokens do not name. Add the token or use one that exists.',
+    category: 'color', kind: 'quality', detect: ['engine'], confidence: 'MEDIUM', tier: 'ask', impact: 'medium',
+    handoff: 'polish', source: 'impeccable',
+  },
+  {
+    id: 'design-system-radius', impeccableId: 'design-system-radius', name: 'Off-system radius',
+    prose: 'A radius DESIGN.md tokens do not name. Add the token or use one that exists.',
+    category: 'surface', kind: 'quality', detect: ['engine'], confidence: 'MEDIUM', tier: 'ask', impact: 'medium',
+    handoff: 'polish', source: 'impeccable',
+  },
+  {
+    id: 'design-system-font-size', impeccableId: 'design-system-font-size', name: 'Off-system font size',
+    prose: 'A font size DESIGN.md tokens do not name. Add the token or use one on the scale.',
+    category: 'type', kind: 'quality', detect: ['engine'], confidence: 'MEDIUM', tier: 'ask', impact: 'medium',
+    handoff: 'polish', source: 'impeccable',
+  },
+];
+
+// ── Fonts ──
+
+/** Never the display voice on Persuade/Experience; the detector flags several as `overused-font`. */
+export const OVERUSED_FONTS_DISPLAY: readonly string[] = OVERUSED_DISPLAY;
+
+/** Never, in any role. */
+export const BANNED_FONTS: readonly string[] = [
+  'Papyrus', 'Comic Sans', 'Lobster', 'Impact', 'Jokerman', 'Bleeding Cowboys', 'Permanent Marker',
+  'Bradley Hand', 'Brush Script', 'Hobo', 'Trajan', 'Raleway', 'Clash Display', 'Courier New (for body)',
+];
+
+/** On the overused list, yet fine as body or UI on an Operate or Read surface when the proposal says so. */
+export const FONTS_BODY_UI_OK: readonly string[] = ['DM Sans', 'Instrument Sans', 'IBM Plex Sans'];
+
+/** Mono for data and code. */
+export const FONTS_MONO_OK: readonly string[] = ['JetBrains Mono', 'IBM Plex Mono', 'Fira Code'];
+
+/**
+ * Freely available faces on no default list. Availability was verified at the
+ * last edit of this constant; a proposal re-verifies in-session before naming one.
+ */
+export const FONTS_VERIFIED_FREE = {
+  verified: '2026-09-08',
+  fontshare: ['Satoshi', 'General Sans', 'Clash Grotesk', 'Cabinet Grotesk'],
+  googleFonts: ['Instrument Serif', 'Source Sans 3', 'JetBrains Mono', 'Fira Code'],
+} as const;
+
+// ── Lookups ──
+
+const BY_ID = new Map(DESIGN_SLOP_CATALOG.map(e => [e.id, e]));
+const BY_IMPECCABLE_ID = new Map(
+  DESIGN_SLOP_CATALOG.filter(e => e.impeccableId).map(e => [e.impeccableId as string, e]),
+);
+
+export function catalogEntry(id: string): DesignSlopEntry | undefined {
+  return BY_ID.get(id);
+}
+
+/** The catalog entry for a detector rule id, or undefined when the id is unmapped. */
+export function entryForImpeccableId(impeccableId: string): DesignSlopEntry | undefined {
+  return BY_IMPECCABLE_ID.get(impeccableId);
+}
+
+// ── Rendering ──
+
+export interface RenderCatalogOptions {
+  kind?: 'slop' | 'quality';
+  category?: SlopCategory;
+  /** drop entries whose impact is in this list (e.g. ['polish'] for a shorter list) */
+  omitImpact?: Impact[];
+  /**
+   * bullets: `- prose` (design-consultation, design-shotgun: prose only, no ids)
+   * ids:     `- [impeccableId] prose`, bracket only when the detector knows the id
+   * compact: `id: name; id: name; ...` on one line
+   */
+  style: 'bullets' | 'ids' | 'compact';
+}
+
+export function selectCatalog(o: Omit<RenderCatalogOptions, 'style'>): DesignSlopEntry[] {
+  return DESIGN_SLOP_CATALOG.filter(e =>
+    (!o.kind || e.kind === o.kind)
+    && (!o.category || e.category === o.category)
+    && !(o.omitImpact && o.omitImpact.includes(e.impact)),
+  );
+}
+
+export function renderCatalog(o: RenderCatalogOptions): string {
+  const entries = selectCatalog(o);
+  switch (o.style) {
+    case 'bullets':
+      return entries.map(e => `- ${e.prose}`).join('\n');
+    case 'ids':
+      return entries.map(e => (e.impeccableId ? `- [${e.impeccableId}] ${e.prose}` : `- ${e.prose}`)).join('\n');
+    case 'compact':
+      return entries.map(e => `${e.impeccableId ?? e.id}: ${e.name}`).join('; ');
+  }
+}
diff --git a/scripts/resolvers/constants.ts b/scripts/resolvers/constants.ts
index 4e94b986e..1599cacf7 100644
--- a/scripts/resolvers/constants.ts
+++ b/scripts/resolvers/constants.ts
@@ -1,26 +1,18 @@
 // ─── Shared Design Constants ────────────────────────────────
 
+import { DESIGN_SLOP_CATALOG } from '../../lib/design-catalog';
+
 /**
  * gstack's AI slop anti-patterns — shared between DESIGN_METHODOLOGY and DESIGN_HARD_RULES.
  *
- * Overused fonts worth calling out in templates (not a pattern to blacklist, but a
- * convergence risk): Inter, Roboto, Arial, Helvetica, Open Sans, Lato, Montserrat,
- * Poppins, and increasingly Space Grotesk. Every AI design tool picks one of these.
- * Design prompts should bias toward less-common display faces.
+ * Derived from the typed catalog in lib/design-catalog.ts: the 11 entries flagged
+ * `legacyBlacklist`, prose verbatim, in catalog order. Overused fonts live there
+ * too (OVERUSED_FONTS_DISPLAY), role-scoped: banned as the display voice, several
+ * still fine as body/UI on an Operate or Read surface.
  */
-export const AI_SLOP_BLACKLIST = [
-  'Purple/violet/indigo gradient backgrounds or blue-to-purple color schemes',
-  '**The 3-column feature grid:** icon-in-colored-circle + bold title + 2-line description, repeated 3x symmetrically. THE most recognizable AI layout.',
-  'Icons in colored circles as section decoration (SaaS starter template look)',
-  'Centered everything (`text-align: center` on all headings, descriptions, cards)',
-  'Uniform bubbly border-radius on every element (same large radius on everything)',
-  'Decorative blobs, floating circles, wavy SVG dividers (if a section feels empty, it needs better content, not decoration)',
-  'Emoji as design elements (rockets in headings, emoji as bullet points)',
-  'Colored left-border on cards (`border-left: 3px solid <accent>`)',
-  'Generic hero copy ("Welcome to [X]", "Unlock the power of...", "Your all-in-one solution for...")',
-  'Cookie-cutter section rhythm (hero → 3 features → testimonials → pricing → CTA, every section same height)',
-  'system-ui or `-apple-system` as the PRIMARY display/body font — the "I gave up on typography" signal. Pick a real typeface.',
-];
+export const AI_SLOP_BLACKLIST: string[] = DESIGN_SLOP_CATALOG
+  .filter(e => e.legacyBlacklist)
+  .map(e => e.prose);
 
 /** OpenAI hard rejection criteria (from "Designing Delightful Frontends with GPT-5.4", Mar 2026) */
 export const OPENAI_HARD_REJECTIONS = [
diff --git a/test/design-catalog.test.ts b/test/design-catalog.test.ts
new file mode 100644
index 000000000..53b67b698
--- /dev/null
+++ b/test/design-catalog.test.ts
@@ -0,0 +1,200 @@
+/**
+ * lib/design-catalog.ts invariants.
+ *
+ * The catalog is the single source of truth for gstack's design anti-pattern
+ * vocabulary. These pins keep it honest against the detector registry fixture
+ * (a bracketed id must be one the engine can emit), keep the 11 legacy lines
+ * byte-identical to what the generated skills already carry, and keep the
+ * module pure enough for bin/ to import at runtime on every host.
+ */
+import { describe, test, expect } from 'bun:test';
+import * as fs from 'fs';
+import * as path from 'path';
+import { spawnSync } from 'child_process';
+import {
+  DESIGN_SLOP_CATALOG, HANDOFF_COMMANDS, OVERUSED_FONTS_DISPLAY, BANNED_FONTS,
+  FONTS_BODY_UI_OK, FONTS_MONO_OK, FONTS_VERIFIED_FREE,
+  catalogEntry, entryForImpeccableId, renderCatalog, selectCatalog,
+} from '../lib/design-catalog';
+import { AI_SLOP_BLACKLIST } from '../scripts/resolvers/constants';
+
+const ROOT = path.join(import.meta.dir, '..');
+const registry = JSON.parse(fs.readFileSync(path.join(ROOT, 'test', 'fixtures', 'impeccable-antipatterns.json'), 'utf-8'));
+const registryById = new Map<string, { id: string; category: string }>(registry.rules.map((r: any) => [r.id, r]));
+
+const CATEGORIES = ['scaffold', 'surface', 'type', 'color', 'layout', 'motion', 'copy', 'states', 'imagery', 'browser-surface'];
+
+describe('catalog shape', () => {
+  test('ids are unique kebab-case and every field is in its domain', () => {
+    const ids = new Set<string>();
+    for (const e of DESIGN_SLOP_CATALOG) {
+      expect(e.id).toMatch(/^[a-z0-9]+(-[a-z0-9]+)*$/);
+      expect(ids.has(e.id)).toBe(false);
+      ids.add(e.id);
+      expect(e.name.length).toBeGreaterThan(0);
+      expect(e.prose.length).toBeGreaterThan(0);
+      expect(CATEGORIES).toContain(e.category);
+      expect(['slop', 'quality']).toContain(e.kind);
+      expect(e.detect.length).toBeGreaterThan(0);
+      for (const d of e.detect) expect(['engine', 'grep', 'render', 'llm']).toContain(d);
+      expect(['HIGH', 'MEDIUM', 'LOW']).toContain(e.confidence);
+      expect(['auto-fix', 'ask', 'possible']).toContain(e.tier);
+      expect(['high', 'medium', 'polish']).toContain(e.impact);
+      expect(['gstack', 'impeccable', 'both']).toContain(e.source);
+    }
+  });
+
+  test('impeccableId equals id, is unique, and exists in the registry fixture', () => {
+    const seen = new Set<string>();
+    for (const e of DESIGN_SLOP_CATALOG.filter(x => x.impeccableId)) {
+      expect(e.impeccableId).toBe(e.id);
+      expect(seen.has(e.impeccableId!)).toBe(false);
+      seen.add(e.impeccableId!);
+      expect(registryById.has(e.impeccableId!)).toBe(true);
+      expect(e.kind).toBe(registryById.get(e.impeccableId!)!.category);
+      expect(e.detect).toContain('engine');
+      expect(['impeccable', 'both']).toContain(e.source);
+    }
+  });
+
+  test('every registry rule is mapped: zero unmapped ids from a current engine', () => {
+    for (const id of registryById.keys()) {
+      expect(entryForImpeccableId(id)?.impeccableId).toBe(id);
+    }
+    expect(DESIGN_SLOP_CATALOG.filter(e => e.impeccableId).length).toBe(registry.rules.length);
+  });
+
+  test('gstack-only entries never claim engine detection or an impeccable source', () => {
+    for (const e of DESIGN_SLOP_CATALOG.filter(x => !x.impeccableId)) {
+      expect(e.detect).not.toContain('engine');
+      expect(e.source).toBe('gstack');
+      expect(registryById.has(e.id)).toBe(false);
+    }
+  });
+
+  test('handoff is one of the eight commands; roles present iff values present', () => {
+    expect(HANDOFF_COMMANDS.length).toBe(8);
+    for (const e of DESIGN_SLOP_CATALOG) {
+      if (e.handoff) expect(HANDOFF_COMMANDS).toContain(e.handoff);
+      expect(Boolean(e.values)).toBe(Boolean(e.roles));
+    }
+  });
+
+  test('grep-detectable entries carry a heuristic; heuristics only on grep entries', () => {
+    for (const e of DESIGN_SLOP_CATALOG) {
+      expect(Boolean(e.heuristic)).toBe(e.detect.includes('grep'));
+    }
+  });
+
+  test('auto-fix is reserved for mechanical CSS fixes with HIGH confidence', () => {
+    for (const e of DESIGN_SLOP_CATALOG.filter(x => x.tier === 'auto-fix')) {
+      expect(e.confidence).toBe('HIGH');
+      expect(e.kind).toBe('quality');
+    }
+    expect(catalogEntry('tiny-text')!.tier).toBe('auto-fix');
+  });
+
+  test('advisory em-dash rule is possible/polish so it never blocks', () => {
+    const e = catalogEntry('em-dash-overuse')!;
+    expect(e.tier).toBe('possible');
+    expect(e.impact).toBe('polish');
+  });
+});
+
+describe('legacy blacklist derivation', () => {
+  test('exactly 11 legacy entries whose prose is AI_SLOP_BLACKLIST, in order', () => {
+    const legacy = DESIGN_SLOP_CATALOG.filter(e => e.legacyBlacklist);
+    expect(legacy.length).toBe(11);
+    expect(legacy.map(e => e.prose)).toEqual(AI_SLOP_BLACKLIST);
+    expect(AI_SLOP_BLACKLIST[0]).toBe('Purple/violet/indigo gradient backgrounds or blue-to-purple color schemes');
+    expect(AI_SLOP_BLACKLIST[1]).toContain('3-column feature grid');
+    expect(AI_SLOP_BLACKLIST[7]).toContain('border-left: 3px solid');
+  });
+
+  test('legacy lines map to real detector ids where one exists', () => {
+    expect(catalogEntry('ai-color-palette')!.legacyBlacklist).toBe(true);
+    expect(catalogEntry('side-tab')!.legacyBlacklist).toBe(true);
+    expect(catalogEntry('uniform-radius')!.impeccableId).toBeUndefined();
+  });
+});
+
+describe('fonts', () => {
+  test('overused display list is the overused-font entry, role-scoped to display', () => {
+    const e = catalogEntry('overused-font')!;
+    expect(e.values).toEqual([...OVERUSED_FONTS_DISPLAY]);
+    expect(e.roles).toEqual(['display']);
+    for (const f of ['Inter', 'Roboto', 'Fraunces', 'Geist', 'Plus Jakarta Sans', 'Space Grotesk', 'DM Sans', 'Instrument Sans', 'IBM Plex Sans']) {
+      expect(OVERUSED_FONTS_DISPLAY).toContain(f);
+    }
+  });
+
+  test('body/UI exceptions are on the overused list; the verified-free faces are not', () => {
+    for (const f of FONTS_BODY_UI_OK) expect(OVERUSED_FONTS_DISPLAY).toContain(f);
+    for (const f of [...FONTS_VERIFIED_FREE.fontshare, ...FONTS_VERIFIED_FREE.googleFonts]) {
+      expect(OVERUSED_FONTS_DISPLAY).not.toContain(f);
+      expect(BANNED_FONTS).not.toContain(f);
+    }
+    expect(FONTS_VERIFIED_FREE.verified).toMatch(/^\d{4}-\d{2}-\d{2}$/);
+  });
+
+  test('banned fonts and overused fonts do not overlap; mono list is mono', () => {
+    for (const f of BANNED_FONTS) expect(OVERUSED_FONTS_DISPLAY).not.toContain(f);
+    for (const f of FONTS_MONO_OK) expect(f).toMatch(/Mono|Code/);
+  });
+});
+
+describe('renderCatalog', () => {
+  test('ids style brackets only detector-known ids', () => {
+    const out = renderCatalog({ kind: 'slop', style: 'ids' });
+    expect(out).toContain('- [nested-cards] ');
+    expect(out).toContain('- [side-tab] ');
+    for (const e of DESIGN_SLOP_CATALOG.filter(x => !x.impeccableId)) {
+      expect(out).not.toContain(`[${e.id}]`);
+    }
+    // gstack-only prose still renders, unbracketed
+    expect(out).toContain('- ' + catalogEntry('hero-metrics')!.prose);
+  });
+
+  test('bullets style renders prose only, no ids anywhere', () => {
+    const out = renderCatalog({ kind: 'slop', style: 'bullets' });
+    expect(out).not.toMatch(/^- \[/m);
+    expect(out.split('\n').length).toBe(selectCatalog({ kind: 'slop' }).length);
+    for (const line of AI_SLOP_BLACKLIST) expect(out).toContain(`- ${line}`);
+  });
+
+  test('compact style is one line of id: name pairs', () => {
+    const out = renderCatalog({ kind: 'quality', style: 'compact' });
+    expect(out.includes('\n')).toBe(false);
+    expect(out).toContain('low-contrast: Low contrast text');
+    expect(out.split('; ').length).toBe(selectCatalog({ kind: 'quality' }).length);
+  });
+
+  test('filters compose: category and omitImpact', () => {
+    const copy = selectCatalog({ kind: 'slop', category: 'copy' });
+    expect(copy.every(e => e.category === 'copy')).toBe(true);
+    const noPolish = selectCatalog({ kind: 'slop', omitImpact: ['polish'] });
+    expect(noPolish.some(e => e.impact === 'polish')).toBe(false);
+    expect(noPolish.length).toBeLessThan(selectCatalog({ kind: 'slop' }).length);
+  });
+});
+
+describe('module purity', () => {
+  test('imports nothing (no I/O, no scripts/); loading it prints nothing', () => {
+    const file = path.join(ROOT, 'lib', 'design-catalog.ts');
+    const src = fs.readFileSync(file, 'utf-8');
+    const imports = src.split('\n').filter(l => /^\s*import\s/.test(l));
+    for (const line of imports) {
+      expect(line).toMatch(/from ['"](\.\/|node:)/);
+      expect(line).not.toContain('scripts/');
+    }
+    const r = spawnSync(process.execPath, ['--no-env-file', '-e', `await import(${JSON.stringify(file)})`], { encoding: 'utf-8', timeout: 30_000 });
+    expect(r.status).toBe(0);
+    expect(r.stdout).toBe('');
+    expect(r.stderr).toBe('');
+  });
+
+  test('carries the Apache-2.0 derivation notice', () => {
+    const src = fs.readFileSync(path.join(ROOT, 'lib', 'design-catalog.ts'), 'utf-8');
+    expect(src).toContain('pbakaus/impeccable (Apache-2.0), modified. See NOTICE.md.');
+  });
+});