feat: design system overhaul — sidebar, AI chats, settings, brainstorm, color cleanup

- Sidebar: dynamic brand-accent colors, brainstorm section restyled
- AI chat general: popup panel with expand/collapse, hides when contextual AI open
- AI chat contextual: tabs reordered (Actions first), X close button, height fix
- Settings: all tabs restyled, 6 new color presets (sage, terracotta, iron, etc.)
- Global color cleanup: emerald/orange hardcoded → brand-accent dynamic
- Brainstorm page: orange → brand-accent throughout
- PageEntry animation component added to key pages
- Floating AI button: bg-brand-accent instead of hardcoded black
- i18n: all 15 locales updated with new AI/billing keys
- Billing: freemium quota tracking, BYOK, stripe subscription scaffolding
- Admin: integrated into new design
- AGENTS.md + CLAUDE.md project rules added

.agent/skills/wds-4-ux-design/templates/instructions/accessibility.instructions.md

@@ -0,0 +1,102 @@
+# Accessibility Specification
+
+**Include when:** Specifying interactive elements, forms, or navigation
+
+---
+
+## For Each Interactive Element
+
+When documenting buttons, links, inputs, add:
+
+```markdown
+| Property | Value |
+|----------|-------|
+| aria-label | "{What it does}" |
+| Keyboard | {Enter / Space / Arrow keys} |
+| Focus style | {ring / outline / highlight} |
+```
+
+**Example:**
+```markdown
+#### Submit Button
+**OBJECT ID:** `form-submit`
+
+| Property | Value |
+|----------|-------|
+| aria-label | "Submit booking request" |
+| Keyboard | Enter or Space |
+| Focus | 2px blue ring |
+| Disabled state | aria-disabled="true", gray, no focus |
+```
+
+---
+
+## Tab Order
+
+Document the logical sequence:
+
+```markdown
+## Keyboard Flow
+
+1. `header-logo` → Home link
+2. `header-nav` → Main navigation
+3. `main-content` → Skip to here
+4. `form-name` → First input
+5. `form-email` → Second input
+6. `form-submit` → Submit button
+```
+
+---
+
+## Dynamic Content
+
+When content changes without page reload:
+
+```markdown
+| Element | Announces |
+|---------|-----------|
+| `toast-success` | aria-live="polite" — "Booking confirmed" |
+| `error-message` | aria-live="assertive" — Error text |
+| `loading-spinner` | aria-busy="true" on parent |
+```
+
+---
+
+## Color Independence
+
+For status indicators, ensure alternatives:
+
+| Status | Color | Also Has |
+|--------|-------|----------|
+| Success | Green | Checkmark icon + "Complete" text |
+| Error | Red | Warning icon + error message |
+| Active | Blue | Bold text + underline |
+
+---
+
+## Form Errors
+
+Link errors to fields:
+
+```markdown
+#### Email Error
+**OBJECT ID:** `form-email-error`
+
+| Property | Value |
+|----------|-------|
+| aria-describedby | Links to `form-email` |
+| Role | "alert" |
+| Content | "Please enter a valid email" |
+```
+
+---
+
+## Quick Checks
+
+Before finalizing:
+
+- [ ] Every button has aria-label or visible text
+- [ ] Every image has alt (or alt="" if decorative)
+- [ ] Every input has associated label
+- [ ] Focus visible on all interactive elements
+- [ ] Status not conveyed by color alone