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/card.cljc

@@ -0,0 +1,67 @@
+(ns ui.card
+  (:require [clojure.string :as str]))
+
+(defn card-class-list
+  "Generate a vector of CSS class strings for a card."
+  [_opts]
+  ["card"])
+
+(defn card-classes
+  "Generate CSS class string for a card."
+  [opts]
+  (str/join " " (card-class-list opts)))
+
+(defn card
+  "Render a card element.
+
+   Props:
+     :class - additional CSS classes
+     :attrs - additional HTML attributes"
+  [{:keys [class attrs] :as _props} & children]
+  #?(:squint
+     (let [classes (cond-> (card-classes {})
+                     class (str " " class))
+           base-attrs (merge {:class classes} attrs)]
+       (into [:article base-attrs] children))
+
+     :cljs
+     (let [cls (card-class-list {})
+           classes (cond-> cls class (conj class))
+           base-attrs (merge {:class classes} attrs)]
+       (into [:article base-attrs] children))
+
+     :clj
+     (let [classes (cond-> (card-classes {})
+                     class (str " " class))
+           base-attrs (merge {:class classes} attrs)]
+       (into [:article base-attrs] children))))
+
+(defn card-header
+  "Render a card header section."
+  [{:keys [class attrs] :as _props} & children]
+  #?(:squint
+     (into [:header (merge {:class (cond-> "card-header" class (str " " class))} attrs)] children)
+     :cljs
+     (into [:header (merge {:class (cond-> ["card-header"] class (conj class))} attrs)] children)
+     :clj
+     (into [:header (merge {:class (cond-> "card-header" class (str " " class))} attrs)] children)))
+
+(defn card-body
+  "Render a card body section."
+  [{:keys [class attrs] :as _props} & children]
+  #?(:squint
+     (into [:div (merge {:class (cond-> "card-body" class (str " " class))} attrs)] children)
+     :cljs
+     (into [:div (merge {:class (cond-> ["card-body"] class (conj class))} attrs)] children)
+     :clj
+     (into [:div (merge {:class (cond-> "card-body" class (str " " class))} attrs)] children)))
+
+(defn card-footer
+  "Render a card footer section."
+  [{:keys [class attrs] :as _props} & children]
+  #?(:squint
+     (into [:footer (merge {:class (cond-> "card-footer" class (str " " class))} attrs)] children)
+     :cljs
+     (into [:footer (merge {:class (cond-> ["card-footer"] class (conj class))} attrs)] children)
+     :clj
+     (into [:footer (merge {:class (cond-> "card-footer" class (str " " class))} attrs)] children)))