v0.2.0: WCAG 2.2 AAA accessibility + toggle fix + version bump

- Upgrade accessibility from WCAG 2.1 AA to WCAG 2.2 AAA conformance
- 42 accessibility fixes across 18 frontend components
- Enhanced contrast ratios (7:1 body text, 4.5:1 large text, 3:1 non-text)
- 44px minimum touch/click targets on all interactive elements
- Full WAI-ARIA 1.2: tablist, radiogroup, alertdialog, progressbar, switch
- Screen-reader-only data tables behind chart, dynamic page titles
- Skip navigation link, semantic heading hierarchy (h1 > h2)
- Celebration popups persist on hover/focus with keyboard dismiss
- Fix ToggleSwitch visual height (44px hit area, 28px visual track)
- Update README with detailed WCAG 2.2 AAA accessibility section
- Include WCAG design doc and implementation plan in docs/plans/

README.md

@@ -21,7 +21,7 @@
   <img src="https://img.shields.io/badge/svelte-5-FF3E00?style=flat-square&logo=svelte&logoColor=white" alt="Svelte 5" />
   <img src="https://img.shields.io/badge/rust-2021-000000?style=flat-square&logo=rust&logoColor=white" alt="Rust" />
   <img src="https://img.shields.io/badge/tailwind-v4-06B6D4?style=flat-square&logo=tailwindcss&logoColor=white" alt="Tailwind v4" />
-  <img src="https://img.shields.io/badge/WCAG_2.1-AA-228B22?style=flat-square" alt="WCAG 2.1 AA" />
+  <img src="https://img.shields.io/badge/WCAG_2.2-AAA-228B22?style=flat-square&logo=w3c&logoColor=white" alt="WCAG 2.2 AAA" />
 </p>
 
 <p align="center">
@@ -320,19 +320,52 @@ Native Windows toast notifications for:
 
 ### ♿ Accessibility
 
-Core Cooldown targets **WCAG 2.1 Level AA** compliance. A break timer for preventing repetitive strain injury should be usable by everyone - including those who already live with disabilities.
+<p>
+  <img src="https://img.shields.io/badge/WCAG_2.2-AAA_Conformance-228B22?style=for-the-badge&logo=w3c&logoColor=white" alt="WCAG 2.2 AAA Conformance" />
+  <img src="https://img.shields.io/badge/since-v0.2.0-blue?style=for-the-badge" alt="Since v0.2.0" />
+</p>
 
-| | Feature | Description |
-|:--|:--------|:------------|
-| ⌨️ | **Full keyboard navigation** | Every control reachable and operable via keyboard alone. Arrow keys navigate dropdowns, adjust color pickers, steppers, and time spinners. Tab/Shift+Tab cycles through all interactive elements. |
-| 🔍 | **Visible focus indicators** | Global `:focus-visible` outlines on all interactive elements - no hidden or suppressed focus rings |
-| 🗣️ | **Screen reader support** | `aria-live` regions announce timer state, breathing phase, break activities, and status changes. Progress rings use `role="progressbar"` with value text. Accordion panels have `aria-controls` and `aria-expanded`. Custom dropdowns support `role="listbox"` with arrow key navigation. |
-| 🎯 | **Focus management** | View transitions move focus to the new view's heading. Break screen traps focus to prevent interaction with obscured content. Dropdown focus returns to trigger on close. |
-| 🎨 | **Color contrast** | All text meets 4.5:1 minimum contrast ratio against dark backgrounds. Dynamic breathing text color interpolation validated against threshold. |
-| 🖥️ | **Windows High Contrast** | `forced-colors: active` media query maps all theme tokens to system colors |
-| 🐢 | **Reduced motion** | `prefers-reduced-motion` disables all CSS animations/transitions, all JavaScript-driven Web Animations API effects, and momentum scroll physics. No functionality lost - just calmer. |
-| 🏷️ | **Descriptive labels** | All toggle switches, steppers, buttons, dropdowns, and form controls have descriptive accessible names |
-| 👆 | **Touch targets** | Interactive elements meet minimum 32x32px hit areas for comfortable interaction |
+Core Cooldown targets **WCAG 2.2 Level AAA** conformance - the highest level of the Web Content Accessibility Guidelines. A break timer for preventing repetitive strain injury should be usable by everyone, including those who already live with disabilities.
+
+> **Why AAA?** Most applications stop at AA. We went further because the people who benefit most from a break timer - those with repetitive strain injuries, chronic pain, or vision impairments - are the same people who need the strongest accessibility support. AAA isn't a checkbox. It's the right thing to do.
+
+#### Contrast & Visual Design
+
+| | Feature | Standard | Description |
+|:--|:--------|:---------|:------------|
+| 🎨 | **Enhanced text contrast** | AAA 7:1 | All body text meets 7:1 contrast ratio against dark backgrounds. Secondary text `#a8a8a8` on `#000` = 7.28:1. |
+| 🔤 | **Large text contrast** | AAA 4.5:1 | Headings and large text (18px+) meet 4.5:1 minimum. Timer countdown, break titles validated. |
+| 🎯 | **Non-text contrast** | AA 3:1 | UI components (toggles, steppers, rings, chart bars, color swatches) all meet 3:1 against adjacent colors. |
+| 🖥️ | **Windows High Contrast** | AAA | `forced-colors: active` maps all theme tokens to system colors. Full usability in all Windows contrast themes. |
+| 🐢 | **Reduced motion** | AAA | `prefers-reduced-motion` disables all CSS animations, JS Web Animations API effects, and momentum scroll. Zero functionality loss. |
+
+#### Keyboard & Navigation
+
+| | Feature | Standard | Description |
+|:--|:--------|:---------|:------------|
+| ⌨️ | **Full keyboard access** | AAA 2.1.3 | Every control operable via keyboard alone - no exceptions. Arrow keys for color pickers, steppers, radio groups. Tab/Shift+Tab cycles all interactive elements. |
+| 🔍 | **Visible focus indicators** | AAA 2.4.13 | 2px solid white outline with dark shadow fallback on every interactive element. No hidden or suppressed focus rings. |
+| ⏭️ | **Skip navigation** | AA 2.4.1 | Skip-to-content link bypasses the titlebar on Tab. |
+| 🏠 | **Focus management** | AA 2.4.3 | View transitions auto-focus the new view's heading. Break screen traps focus. Dropdown focus returns to trigger on close. |
+| 🏷️ | **Heading structure** | AAA 2.4.10 | Semantic `h1` > `h2` hierarchy across all views. Settings sections use `h2` with `aria-labelledby`. |
+
+#### Screen Readers & Assistive Technology
+
+| | Feature | Standard | Description |
+|:--|:--------|:---------|:------------|
+| 🗣️ | **Live regions** | AA 4.1.3 | `aria-live` announces timer state, breathing phase, break activities, status changes, and celebration events. |
+| 📊 | **Semantic roles** | AA 4.1.2 | `progressbar` on timer rings, `switch` on toggles, `tablist`/`tab`/`tabpanel` on stats view, `radiogroup`/`radio` on breathing patterns, `alertdialog` on overlays. |
+| 📋 | **Data tables** | A 1.3.1 | Screen-reader-only data tables behind the 7-day chart provide the same information non-visually. |
+| 🏷️ | **Accessible names** | AA 4.1.2 | Every toggle, stepper, button, swatch, and form control has a descriptive `aria-label` or visible label. Sound presets use `aria-pressed`. |
+| 📝 | **Page titles** | AAA 2.4.2 | Dynamic `document.title` updates per view ("Core Cooldown - Dashboard", "- Settings", etc.). |
+
+#### Target Sizes & Interaction
+
+| | Feature | Standard | Description |
+|:--|:--------|:---------|:------------|
+| 👆 | **44px touch targets** | AAA 2.5.8 | All interactive elements (buttons, toggles, steppers, color swatches, titlebar controls) have minimum 44x44px hit areas. Visual size may be smaller - the clickable area extends invisibly. |
+| 🎯 | **Celebration persistence** | - | Milestone/goal popups stay visible on hover or focus, with keyboard-accessible dismiss buttons and Escape key support. |
+| ⏱️ | **Hold-to-repeat** | - | Stepper +/- buttons support press-and-hold for continuous increment, with keyboard Enter/Space triggering the same behavior. |
 
 <br />
 
@@ -723,7 +756,7 @@ No contribution agreements to sign. No corporate CLAs. No licensing traps. Every
 
 - Report bugs or rough edges
 - Suggest new break activities (especially with physiotherapy or ergonomics knowledge)
-- Improve accessibility (WCAG 2.1 AA foundation is in place - help us push further)
+- Improve accessibility (WCAG 2.2 AAA foundation is in place - help us maintain it)
 - Port idle detection to macOS/Linux
 - Translate the interface
 - Share it with someone who needs it