Initial commit: TKB Timeshift Schedule Management Application

- Next.js 15.2.4 with React 19 and TypeScript
- Monthly schedule generator with Excel-like formatting
- Complete employee list from example.xlsx (18 employees)
- Excel-style column naming (A, B, C, ..., Z, AA, AB, ...)
- Counter-clockwise text rotation for data values
- Weekend highlighting and shift color coding
- Team selection for TKB, METRO, D8
- 7 days from previous month + full current month date range
- jspreadsheet integration for Excel-like interface

🤖 Generated with [Claude Code](https://claude.ai/code)

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

v0_extracted/components/ui/sonner.tsx

@@ -0,0 +1,31 @@
+"use client"
+
+import { useTheme } from "next-themes"
+import { Toaster as Sonner } from "sonner"
+
+type ToasterProps = React.ComponentProps<typeof Sonner>
+
+const Toaster = ({ ...props }: ToasterProps) => {
+  const { theme = "system" } = useTheme()
+
+  return (
+    <Sonner
+      theme={theme as ToasterProps["theme"]}
+      className="toaster group"
+      toastOptions={{
+        classNames: {
+          toast:
+            "group toast group-[.toaster]:bg-background group-[.toaster]:text-foreground group-[.toaster]:border-border group-[.toaster]:shadow-lg",
+          description: "group-[.toast]:text-muted-foreground",
+          actionButton:
+            "group-[.toast]:bg-primary group-[.toast]:text-primary-foreground",
+          cancelButton:
+            "group-[.toast]:bg-muted group-[.toast]:text-muted-foreground",
+        },
+      }}
+      {...props}
+    />
+  )
+}
+
+export { Toaster }