feat: full shadcn/ui component system with consistent typography

New components:
- ui/button.tsx — Button with primary/accent/surface/ghost/destructive variants
- ui/input.tsx — Input + Textarea with focus ring and CSS var theming
- ui/label.tsx — Radix Label with peer-disabled support
- ui/separator.tsx — Radix Separator
- ui/tooltip.tsx — Radix Tooltip with themed content
- ui/dialog.tsx — Radix Dialog replacing custom modal implementations
- ui/table.tsx — Table/TableHeader/TableBody/TableRow/TableHead/TableCell
- ui/typography.tsx — PageTitle/SectionHeading/Body/Muted/Caption/MonoCaption

Wired throughout all components:
- ConfirmDialog + FormModal migrated to Radix Dialog (focus trap, Escape, ARIA)
- All raw <button> → Button, <input>/<textarea> → Input/Textarea
- All repeated text patterns → typography components
- All hardcoded hex/rgba strings → COLOR constants

package.json

@@ -18,6 +18,11 @@
     "@fontsource/dm-mono": "^5.2.7",
     "@fontsource/dm-sans": "^5.2.8",
     "@radix-ui/react-collapsible": "^1.1.12",
+    "@radix-ui/react-dialog": "^1.1.15",
+    "@radix-ui/react-label": "^2.1.8",
+    "@radix-ui/react-separator": "^1.1.8",
+    "@radix-ui/react-slot": "^1.2.4",
+    "@radix-ui/react-tooltip": "^1.2.8",
     "@tailwindcss/vite": "^4.2.4",
     "@tanstack/react-query": "^5.74.4",
     "@tanstack/react-router": "^1.120.3",