feat: add 13 components adapted from Oat UI

Components (.cljc + .css + tests):
- Alert (success/warning/danger/info variants)
- Badge (primary/secondary/outline/success/warning/danger)
- Card (card/card-header/card-body/card-footer)
- Accordion (collapsible with open/closed state)
- Table (headers/rows, striped/bordered variants)
- Dialog (modal with header/body/footer sections)
- Breadcrumb (nav with active item)
- Pagination (current/total with prev/next)
- Progress (value bar with color variants)
- Spinner (sm/md/lg sizes)
- Skeleton (line/box/circle/heading placeholders)
- Switch (toggle with checked/disabled states)
- Tooltip (hover text via data-tooltip attr)

CSS-only additions:
- Form elements (inputs, selects, checkboxes, radios, range, groups)
- Grid (12-column system with offsets, responsive)
- Utilities (flex, spacing, alignment, sr-only)

Also adds warning/fg-on-warning tokens to light and dark themes.
All 3 dev targets updated with full component showcase.
40 tests, 213 assertions, all passing.

src/ui/switch.cljc

@@ -0,0 +1,65 @@
+(ns ui.switch
+  (:require [clojure.string :as str]))
+
+(defn switch-class-list
+  "Generate a vector of CSS class strings for a switch."
+  [{:keys [disabled]}]
+  (cond-> ["switch"]
+    disabled (conj "switch--disabled")))
+
+(defn switch-classes
+  "Generate CSS class string for a switch."
+  [opts]
+  (str/join " " (switch-class-list opts)))
+
+(defn switch-toggle
+  "Render a toggle switch element.
+
+   Props:
+     :checked   - boolean, whether the switch is on
+     :disabled  - boolean
+     :on-change - change handler (ignored in :clj target)
+     :label     - label text
+     :class     - additional CSS classes
+     :attrs     - additional HTML attributes"
+  [{:keys [checked disabled on-change label class attrs] :as _props}]
+  #?(:squint
+     (let [classes (cond-> (switch-classes {:disabled disabled})
+                     class (str " " class))
+           track-cls (cond-> "switch-track"
+                       checked (str " switch-track--checked"))]
+       [:label (merge {:class classes} attrs)
+        [:input {:class "switch-input" :type "checkbox"
+                 :checked (boolean checked)
+                 :disabled (boolean disabled)
+                 :on-change on-change}]
+        [:span {:class track-cls}
+         [:span {:class "switch-thumb"}]]
+        (when label [:span label])])
+
+     :cljs
+     (let [cls (switch-class-list {:disabled disabled})
+           classes (cond-> cls class (conj class))
+           track-cls (cond-> ["switch-track"]
+                       checked (conj "switch-track--checked"))]
+       [:label (merge {:class classes} attrs)
+        [:input (cond-> {:class ["switch-input"] :type "checkbox"
+                         :checked (boolean checked)
+                         :disabled (boolean disabled)}
+                  on-change (assoc-in [:on :change] on-change))]
+        [:span {:class track-cls}
+         [:span {:class ["switch-thumb"]}]]
+        (when label [:span label])])
+
+     :clj
+     (let [classes (cond-> (switch-classes {:disabled disabled})
+                     class (str " " class))
+           track-cls (cond-> "switch-track"
+                       checked (str " switch-track--checked"))]
+       [:label (merge {:class classes} attrs)
+        [:input {:class "switch-input" :type "checkbox"
+                 :checked (boolean checked)
+                 :disabled (boolean disabled)}]
+        [:span {:class track-cls}
+         [:span {:class "switch-thumb"}]]
+        (when label [:span label])])))