Reorganise components into atoms/molecules/organisms and fix Input icon colours

Moved all 17 components from ui/ into atomic design tiers: atoms (Button,
IconButton, Input, Textarea, Select, Checkbox, Radio, Switch, Badge, Tag,
Chip, Tooltip) and molecules (Alert, Accordion, Card, Dialog, Popover).
Updated all Storybook titles and cross-component imports. Changed Input
icons to primary-dark and replaced palette token references with semantic
tokens.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/components/molecules/Accordion/index.ts

@@ -0,0 +1,7 @@
+export { Accordion, AccordionItem, AccordionTrigger, AccordionContent } from './Accordion'
+export type {
+  AccordionProps,
+  AccordionItemProps,
+  AccordionTriggerProps,
+  AccordionContentProps,
+} from './Accordion'