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/accordion.cljc

@@ -0,0 +1,52 @@
+(ns ui.accordion
+  (:require [clojure.string :as str]))
+
+(defn accordion-class-list
+  "Generate a vector of CSS class strings for an accordion item."
+  [{:keys [open]}]
+  (cond-> ["accordion"]
+    open (conj "accordion--open")))
+
+(defn accordion-classes
+  "Generate CSS class string for an accordion."
+  [opts]
+  (str/join " " (accordion-class-list opts)))
+
+(defn accordion
+  "Render an accordion (collapsible) item.
+
+   Props:
+     :title - trigger text
+     :open  - boolean, whether expanded
+     :class - additional CSS classes
+     :attrs - additional HTML attributes"
+  [{:keys [title open class attrs] :as _props} & children]
+  #?(:squint
+     (let [classes (cond-> (accordion-classes {:open open})
+                     class (str " " class))
+           base-attrs (merge {:class classes} attrs)]
+       (into [:div base-attrs
+              [:div {:class "accordion-trigger"} title]]
+             (when open
+               [[:div {:class "accordion-content"}
+                 (into [:div] children)]])))
+
+     :cljs
+     (let [cls (accordion-class-list {:open open})
+           classes (cond-> cls class (conj class))
+           base-attrs (merge {:class classes} attrs)]
+       (into [:div base-attrs
+              [:div {:class ["accordion-trigger"]} title]]
+             (when open
+               [[:div {:class ["accordion-content"]}
+                 (into [:div] children)]])))
+
+     :clj
+     (let [classes (cond-> (accordion-classes {:open open})
+                     class (str " " class))
+           base-attrs (merge {:class classes} attrs)]
+       (into [:div base-attrs
+              [:div {:class "accordion-trigger"} title]]
+             (when open
+               [[:div {:class "accordion-content"}
+                 (into [:div] children)]])))))