feat(frontend): Implement Issue management and Kanban board

Add comprehensive Issue management functionality with drag-and-drop Kanban board.

Changes:
- Created Issue API client (issues.ts) with CRUD operations
- Implemented React Query hooks for Issue data management
- Added IssueCard component with drag-and-drop support using @dnd-kit
- Created KanbanColumn component with droppable zones
- Built CreateIssueDialog with form validation using zod
- Implemented Kanban page at /projects/[id]/kanban with DnD status changes
- Added missing UI components (textarea, select, skeleton)
- Enhanced API client with helper methods (get, post, put, patch, delete)
- Installed dependencies: @dnd-kit/core, @dnd-kit/sortable, @dnd-kit/utilities, @radix-ui/react-select, sonner
- Fixed SignalR ConnectionManager TypeScript error
- Preserved legacy KanbanBoard component for backward compatibility

Features:
- Drag and drop issues between Backlog, Todo, InProgress, and Done columns
- Real-time status updates via API
- Issue creation with type (Story, Task, Bug, Epic) and priority
- Visual feedback with priority colors and type icons
- Toast notifications for user actions

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

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

components/features/issues/CreateIssueDialog.tsx

@@ -0,0 +1,184 @@
+'use client';
+
+import { useForm } from 'react-hook-form';
+import { zodResolver } from '@hookform/resolvers/zod';
+import { z } from 'zod';
+import { useCreateIssue } from '@/lib/hooks/use-issues';
+import {
+  Dialog,
+  DialogContent,
+  DialogHeader,
+  DialogTitle,
+} from '@/components/ui/dialog';
+import { Button } from '@/components/ui/button';
+import { Input } from '@/components/ui/input';
+import { Textarea } from '@/components/ui/textarea';
+import {
+  Select,
+  SelectContent,
+  SelectItem,
+  SelectTrigger,
+  SelectValue,
+} from '@/components/ui/select';
+import {
+  Form,
+  FormControl,
+  FormField,
+  FormItem,
+  FormLabel,
+  FormMessage,
+} from '@/components/ui/form';
+
+const createIssueSchema = z.object({
+  title: z.string().min(1, 'Title is required'),
+  description: z.string().min(1, 'Description is required'),
+  type: z.enum(['Story', 'Task', 'Bug', 'Epic']),
+  priority: z.enum(['Low', 'Medium', 'High', 'Critical']),
+});
+
+interface CreateIssueDialogProps {
+  projectId: string;
+  open: boolean;
+  onOpenChange: (open: boolean) => void;
+}
+
+export function CreateIssueDialog({
+  projectId,
+  open,
+  onOpenChange,
+}: CreateIssueDialogProps) {
+  const form = useForm({
+    resolver: zodResolver(createIssueSchema),
+    defaultValues: {
+      title: '',
+      description: '',
+      type: 'Task' as const,
+      priority: 'Medium' as const,
+    },
+  });
+
+  const createMutation = useCreateIssue(projectId);
+
+  const onSubmit = (data: z.infer<typeof createIssueSchema>) => {
+    createMutation.mutate(data, {
+      onSuccess: () => {
+        form.reset();
+        onOpenChange(false);
+      },
+    });
+  };
+
+  return (
+    <Dialog open={open} onOpenChange={onOpenChange}>
+      <DialogContent>
+        <DialogHeader>
+          <DialogTitle>Create New Issue</DialogTitle>
+        </DialogHeader>
+        <Form {...form}>
+          <form onSubmit={form.handleSubmit(onSubmit)} className="space-y-4">
+            <FormField
+              control={form.control}
+              name="title"
+              render={({ field }) => (
+                <FormItem>
+                  <FormLabel>Title</FormLabel>
+                  <FormControl>
+                    <Input placeholder="Issue title..." {...field} />
+                  </FormControl>
+                  <FormMessage />
+                </FormItem>
+              )}
+            />
+
+            <FormField
+              control={form.control}
+              name="description"
+              render={({ field }) => (
+                <FormItem>
+                  <FormLabel>Description</FormLabel>
+                  <FormControl>
+                    <Textarea
+                      placeholder="Describe the issue..."
+                      rows={4}
+                      {...field}
+                    />
+                  </FormControl>
+                  <FormMessage />
+                </FormItem>
+              )}
+            />
+
+            <div className="grid grid-cols-2 gap-4">
+              <FormField
+                control={form.control}
+                name="type"
+                render={({ field }) => (
+                  <FormItem>
+                    <FormLabel>Type</FormLabel>
+                    <Select
+                      onValueChange={field.onChange}
+                      defaultValue={field.value}
+                    >
+                      <FormControl>
+                        <SelectTrigger>
+                          <SelectValue />
+                        </SelectTrigger>
+                      </FormControl>
+                      <SelectContent>
+                        <SelectItem value="Story">Story</SelectItem>
+                        <SelectItem value="Task">Task</SelectItem>
+                        <SelectItem value="Bug">Bug</SelectItem>
+                        <SelectItem value="Epic">Epic</SelectItem>
+                      </SelectContent>
+                    </Select>
+                    <FormMessage />
+                  </FormItem>
+                )}
+              />
+
+              <FormField
+                control={form.control}
+                name="priority"
+                render={({ field }) => (
+                  <FormItem>
+                    <FormLabel>Priority</FormLabel>
+                    <Select
+                      onValueChange={field.onChange}
+                      defaultValue={field.value}
+                    >
+                      <FormControl>
+                        <SelectTrigger>
+                          <SelectValue />
+                        </SelectTrigger>
+                      </FormControl>
+                      <SelectContent>
+                        <SelectItem value="Low">Low</SelectItem>
+                        <SelectItem value="Medium">Medium</SelectItem>
+                        <SelectItem value="High">High</SelectItem>
+                        <SelectItem value="Critical">Critical</SelectItem>
+                      </SelectContent>
+                    </Select>
+                    <FormMessage />
+                  </FormItem>
+                )}
+              />
+            </div>
+
+            <div className="flex justify-end gap-2">
+              <Button
+                type="button"
+                variant="outline"
+                onClick={() => onOpenChange(false)}
+              >
+                Cancel
+              </Button>
+              <Button type="submit" disabled={createMutation.isPending}>
+                {createMutation.isPending ? 'Creating...' : 'Create Issue'}
+              </Button>
+            </div>
+          </form>
+        </Form>
+      </DialogContent>
+    </Dialog>
+  );
+}