feat(17-03): create CreateInitiativeDialog with shadcn primitives

- Install shadcn Dialog, Input, Label, Textarea components
- Move from @/ literal dir to src/components/ui/ (known shadcn CLI issue)
- CreateInitiativeDialog: controlled dialog with name/description fields
- tRPC createInitiative mutation with loading/error states
- Form resets on open, validates name non-empty

packages/web/src/components/CreateInitiativeDialog.tsx

@@ -0,0 +1,115 @@
+import { useEffect, useState } from "react";
+import {
+  Dialog,
+  DialogContent,
+  DialogDescription,
+  DialogFooter,
+  DialogHeader,
+  DialogTitle,
+} from "@/components/ui/dialog";
+import { Button } from "@/components/ui/button";
+import { Input } from "@/components/ui/input";
+import { Label } from "@/components/ui/label";
+import { Textarea } from "@/components/ui/textarea";
+import { trpc } from "@/lib/trpc";
+
+interface CreateInitiativeDialogProps {
+  open: boolean;
+  onOpenChange: (open: boolean) => void;
+}
+
+export function CreateInitiativeDialog({
+  open,
+  onOpenChange,
+}: CreateInitiativeDialogProps) {
+  const [name, setName] = useState("");
+  const [description, setDescription] = useState("");
+  const [error, setError] = useState<string | null>(null);
+
+  const utils = trpc.useUtils();
+
+  const createMutation = trpc.createInitiative.useMutation({
+    onSuccess: () => {
+      utils.listInitiatives.invalidate();
+      onOpenChange(false);
+    },
+    onError: (err) => {
+      setError(err.message);
+    },
+  });
+
+  // Reset form when dialog opens
+  useEffect(() => {
+    if (open) {
+      setName("");
+      setDescription("");
+      setError(null);
+    }
+  }, [open]);
+
+  function handleSubmit(e: React.FormEvent) {
+    e.preventDefault();
+    setError(null);
+    createMutation.mutate({
+      name: name.trim(),
+      description: description.trim() || undefined,
+    });
+  }
+
+  const canSubmit = name.trim().length > 0 && !createMutation.isPending;
+
+  return (
+    <Dialog open={open} onOpenChange={onOpenChange}>
+      <DialogContent>
+        <DialogHeader>
+          <DialogTitle>Create Initiative</DialogTitle>
+          <DialogDescription>
+            Create a new initiative to plan and execute work.
+          </DialogDescription>
+        </DialogHeader>
+        <form onSubmit={handleSubmit} className="space-y-4">
+          <div className="space-y-2">
+            <Label htmlFor="initiative-name">Name</Label>
+            <Input
+              id="initiative-name"
+              placeholder="e.g. User Authentication"
+              value={name}
+              onChange={(e) => setName(e.target.value)}
+              autoFocus
+            />
+          </div>
+          <div className="space-y-2">
+            <Label htmlFor="initiative-description">
+              Description{" "}
+              <span className="text-muted-foreground font-normal">
+                (optional)
+              </span>
+            </Label>
+            <Textarea
+              id="initiative-description"
+              placeholder="Brief description of the initiative..."
+              value={description}
+              onChange={(e) => setDescription(e.target.value)}
+              rows={3}
+            />
+          </div>
+          {error && (
+            <p className="text-sm text-destructive">{error}</p>
+          )}
+          <DialogFooter>
+            <Button
+              type="button"
+              variant="outline"
+              onClick={() => onOpenChange(false)}
+            >
+              Cancel
+            </Button>
+            <Button type="submit" disabled={!canSubmit}>
+              {createMutation.isPending ? "Creating..." : "Create"}
+            </Button>
+          </DialogFooter>
+        </form>
+      </DialogContent>
+    </Dialog>
+  );
+}