feat(ux): Sprint 1 — quick wins: EmptyState, DateRangePresets, debounce, save feedback, scenarios nav

- EmptyState shared component; replace AllocationsClient inline empty state
- DateRangePresets (this month/quarter/3 months/year) integrated into AllocationModal
- Debounce conflict-check inputs in AllocationModal (400ms) using existing useDebounce
- Dashboard layout save feedback via SuccessToast after DB write completes
- Scenarios nav item in Planning sidebar + /scenarios list page

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

apps/web/src/components/allocations/AllocationModal.tsx

@@ -1,6 +1,7 @@
 "use client";
 
 import { useState, useEffect, useMemo } from "react";
+import { useDebounce } from "~/hooks/useDebounce.js";
 import { AnimatedModal } from "~/components/ui/AnimatedModal.js";
 import { useInvalidatePlanningViews } from "~/hooks/useInvalidatePlanningViews.js";
 import { AllocationStatus } from "@capakraken/shared";
@@ -9,6 +10,7 @@ import { trpc } from "~/lib/trpc/client.js";
 import { getPlanningEntryMutationId } from "~/lib/planningEntryIds.js";
 import { toDateInputValue } from "~/lib/format.js";
 import { DateInput } from "~/components/ui/DateInput.js";
+import { DateRangePresets } from "~/components/ui/DateRangePresets.js";
 import { RecurrenceEditor } from "./RecurrenceEditor.js";
 import { InfoTooltip } from "~/components/ui/InfoTooltip.js";
 import { ConflictWarningPanel } from "./ConflictWarningPanel.js";
@@ -71,22 +73,28 @@ export function AllocationModal({ allocation, onClose, onSuccess }: AllocationMo
     { enabled: shouldCheckOverlap, staleTime: 30_000 },
   );
 
+  // Debounce conflict-check inputs so we don't fire on every keystroke/interaction.
+  const debouncedResourceId = useDebounce(resourceId, 400);
+  const debouncedStartDate = useDebounce(startDate, 400);
+  const debouncedEndDate = useDebounce(endDate, 400);
+  const debouncedHoursPerDay = useDebounce(hoursPerDay, 400);
+
   // Pre-flight conflict check: overbooking + vacation overlap for this resource/period.
-  const conflictCheckStart = startDate ? new Date(startDate) : null;
-  const conflictCheckEnd = endDate ? new Date(endDate) : null;
+  const conflictCheckStart = debouncedStartDate ? new Date(debouncedStartDate) : null;
+  const conflictCheckEnd = debouncedEndDate ? new Date(debouncedEndDate) : null;
   const shouldCheckConflicts =
     !isDemandEntry &&
-    !!resourceId &&
+    !!debouncedResourceId &&
     conflictCheckStart !== null && !isNaN(conflictCheckStart.getTime()) &&
     conflictCheckEnd !== null && !isNaN(conflictCheckEnd.getTime()) &&
-    hoursPerDay > 0;
+    debouncedHoursPerDay > 0;
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
   const { data: conflictResult, isFetching: checkingConflicts } = (trpc.allocation.checkConflicts.useQuery as any)(
     {
-      resourceId,
+      resourceId: debouncedResourceId,
       startDate: conflictCheckStart,
       endDate: conflictCheckEnd,
-      hoursPerDay,
+      hoursPerDay: debouncedHoursPerDay,
       excludeAssignmentId: isEditing && allocation?.id ? allocation.id : undefined,
     },
     { enabled: shouldCheckConflicts, staleTime: 15_000 },
@@ -424,10 +432,15 @@ export function AllocationModal({ allocation, onClose, onSuccess }: AllocationMo
           </div>
 
           {/* Dates */}
-          <div className="grid grid-cols-2 gap-4">
+          <div>
+            <div className="flex items-center justify-between mb-1">
+              <span className={labelClass}>Date Range <span className="text-red-500">*</span></span>
+              <DateRangePresets onSelect={(s, e) => { setStartDate(s); setEndDate(e); }} />
+            </div>
+            <div className="grid grid-cols-2 gap-4">
             <div>
               <label htmlFor="modal-start" className={labelClass}>
-                Start Date <span className="text-red-500">*</span><InfoTooltip content="First day of this allocation period (inclusive)." />
+                Start Date <InfoTooltip content="First day of this allocation period (inclusive)." />
               </label>
               <DateInput
                 id="modal-start"
@@ -439,7 +452,7 @@ export function AllocationModal({ allocation, onClose, onSuccess }: AllocationMo
             </div>
             <div>
               <label htmlFor="modal-end" className={labelClass}>
-                End Date <span className="text-red-500">*</span><InfoTooltip content="Last day of this allocation period (inclusive)." />
+                End Date <InfoTooltip content="Last day of this allocation period (inclusive)." />
               </label>
               <DateInput
                 id="modal-end"
@@ -450,6 +463,7 @@ export function AllocationModal({ allocation, onClose, onSuccess }: AllocationMo
                 required
               />
             </div>
+            </div>
           </div>
 
           {/* Hours/Day + Status */}

apps/web/src/components/allocations/AllocationsClient.tsx

@@ -1,6 +1,7 @@
 "use client";
 
 import { useState, useEffect, useMemo, useCallback, useRef } from "react";
+import { useLocalStorage } from "~/hooks/useLocalStorage.js";
 import { formatDate } from "~/lib/format.js";
 import { trpc } from "~/lib/trpc/client.js";
 import { AllocationModal } from "./AllocationModal.js";
@@ -22,6 +23,7 @@ import { useViewPrefs } from "~/hooks/useViewPrefs.js";
 import { getPlanningEntryMutationId } from "~/lib/planningEntryIds.js";
 import { ALLOCATION_STATUS_BADGE as STATUS_BADGE } from "~/lib/status-styles.js";
 import { SuccessToast } from "~/components/ui/SuccessToast.js";
+import { EmptyState } from "~/components/ui/EmptyState.js";
 import {
   collapseAllAllocationGroups,
   createInitialCollapsedAllocationGroups,
@@ -240,10 +242,7 @@ export function AllocationsClient() {
   );
 
   // ─── View mode: grouped (default) vs flat ──────────────────────────────────
-  const [viewMode, setViewMode] = useState<"grouped" | "flat">(() => {
-    if (typeof window === "undefined") return "grouped";
-    return (localStorage.getItem("capakraken:allocations:viewMode") as "grouped" | "flat") ?? "grouped";
-  });
+  const [viewMode, setViewMode] = useLocalStorage<"grouped" | "flat">("capakraken:allocations:viewMode", "grouped");
   const [collapsedGroups, setCollapsedGroups] = useState<CollapsedAllocationGroups>(
     () => createInitialCollapsedAllocationGroups(),
   );
@@ -252,12 +251,8 @@ export function AllocationsClient() {
   const hasEvaluatedInitialVisibility = useRef(false);
 
   const toggleViewMode = useCallback(() => {
-    setViewMode((prev) => {
-      const next = prev === "grouped" ? "flat" : "grouped";
-      localStorage.setItem("capakraken:allocations:viewMode", next);
-      return next;
-    });
-  }, []);
+    setViewMode((prev) => prev === "grouped" ? "flat" : "grouped");
+  }, [setViewMode]);
 
   type ProjectSubGroup = {
     projectId: string;
@@ -750,20 +745,21 @@ export function AllocationsClient() {
 
             {!isLoading && !allocationQueryFailure && sorted.length === 0 && (
               <tr>
-                <td colSpan={totalColSpan} className="py-12 text-center text-sm text-gray-500 dark:text-gray-400">
-                  <div data-testid="allocations-empty-state" className="flex flex-col items-center gap-2">
-                    <p className="font-medium text-gray-700 dark:text-gray-200">{emptyState.title}</p>
-                    <p>{emptyState.detail}</p>
-                    {emptyState.showResetAction && (
-                      <button
-                        type="button"
-                        onClick={clearAll}
-                        className="rounded-lg border border-gray-300 px-3 py-1.5 text-xs font-medium text-gray-700 transition hover:border-gray-400 hover:bg-gray-50 dark:border-gray-600 dark:text-gray-200 dark:hover:bg-gray-800"
-                      >
-                        Show all assignments
-                      </button>
-                    )}
-                  </div>
+                <td colSpan={totalColSpan}>
+                  {emptyState.showResetAction ? (
+                    <EmptyState
+                      testId="allocations-empty-state"
+                      title={emptyState.title}
+                      detail={emptyState.detail}
+                      action={{ label: "Show all assignments", onClick: clearAll }}
+                    />
+                  ) : (
+                    <EmptyState
+                      testId="allocations-empty-state"
+                      title={emptyState.title}
+                      detail={emptyState.detail}
+                    />
+                  )}
                 </td>
               </tr>
             )}

apps/web/src/components/dashboard/DashboardClient.tsx

@@ -8,6 +8,7 @@ import { useDashboardLayout } from "~/hooks/useDashboardLayout.js";
 import { WidgetContainer } from "./WidgetContainer.js";
 import { AddWidgetModal } from "./AddWidgetModal.js";
 import { getWidget } from "./widget-registry.js";
+import { SuccessToast } from "~/components/ui/SuccessToast.js";
 
 // Import CSS for react-grid-layout
 import "react-grid-layout/css/styles.css";
@@ -146,7 +147,7 @@ function DeferredWidgetBody({
 
 export function DashboardClient() {
   const [addModalOpen, setAddModalOpen] = useState(false);
-  const { config, isHydrated, addWidget, removeWidget, updateWidgetConfig, onLayoutChange, resetLayout } =
+  const { config, isHydrated, saveStatus, addWidget, removeWidget, updateWidgetConfig, onLayoutChange, resetLayout } =
     useDashboardLayout();
 
   // Measure grid container width so Responsive knows the column size.
@@ -331,6 +332,7 @@ export function DashboardClient() {
       )}
 
       {addModalOpen && <AddWidgetModal onAdd={addWidget} onClose={() => setAddModalOpen(false)} />}
+      <SuccessToast show={saveStatus === "saved"} message="Layout saved" variant="info" />
     </div>
   );
 }

apps/web/src/components/layout/AppShell.tsx

@@ -121,6 +121,9 @@ function SettingsIcon() {
 function WebhooksIcon() {
   return <svg className="h-4 w-4" fill="none" stroke="currentColor" viewBox="0 0 24 24"><path strokeLinecap="round" strokeLinejoin="round" strokeWidth={1.8} d="M13.828 10.172a4 4 0 00-5.656 0l-4 4a4 4 0 105.656 5.656l1.102-1.101m-.758-4.899a4 4 0 005.656 0l4-4a4 4 0 00-5.656-5.656l-1.1 1.1" /></svg>;
 }
+function ScenariosIcon() {
+  return <svg className="h-4 w-4" fill="none" stroke="currentColor" viewBox="0 0 24 24"><path strokeLinecap="round" strokeLinejoin="round" strokeWidth={1.8} d="M8 7h12m0 0l-4-4m4 4l-4 4m0 6H4m0 0l4 4m-4-4l4-4" /></svg>;
+}
 
 function CollapseIcon({ collapsed }: { collapsed: boolean }) {
   return (
@@ -162,6 +165,7 @@ const navSections: NavSection[] = [
       { href: "/timeline", label: "Timeline", icon: <TimelineIcon />, roles: ["ADMIN", "MANAGER", "CONTROLLER", "USER", "VIEWER"] },
       { href: "/allocations", label: "Allocations", icon: <AllocationsIcon />, roles: ["ADMIN", "MANAGER", "CONTROLLER"] },
       { href: "/staffing", label: "Staffing", icon: <StaffingIcon />, roles: ["ADMIN", "MANAGER"] },
+      { href: "/scenarios", label: "Scenarios", icon: <ScenariosIcon />, roles: ["ADMIN", "MANAGER", "CONTROLLER"] },
       { href: "/notifications", label: "Notifications", icon: <NotificationsIcon />, roles: ["ADMIN", "MANAGER", "CONTROLLER", "USER", "VIEWER"] },
     ],
   },

apps/web/src/components/scenarios/ScenariosListClient.tsx

@@ -0,0 +1,111 @@
+"use client";
+
+import Link from "next/link";
+import { trpc } from "~/lib/trpc/client.js";
+import { EmptyState } from "~/components/ui/EmptyState.js";
+import { formatDate } from "~/lib/format.js";
+
+const PROJECT_STATUS_BADGE: Record<string, string> = {
+  ACTIVE:    "bg-emerald-100 text-emerald-800 dark:bg-emerald-900/40 dark:text-emerald-300",
+  DRAFT:     "bg-gray-100 text-gray-600 dark:bg-gray-800 dark:text-gray-400",
+  ON_HOLD:   "bg-amber-100 text-amber-800 dark:bg-amber-900/40 dark:text-amber-300",
+  COMPLETED: "bg-blue-100 text-blue-800 dark:bg-blue-900/40 dark:text-blue-300",
+  CANCELLED: "bg-red-100 text-red-700 dark:bg-red-900/40 dark:text-red-300",
+};
+
+export function ScenariosListClient() {
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  const { data, isLoading } = (trpc.project.list.useQuery as any)({ limit: 500 }, { staleTime: 60_000 }) as {
+    data: { projects: Array<{ id: string; shortCode: string; name: string; status: string; startDate: string | null; endDate: string | null; clientId: string | null }> } | undefined;
+    isLoading: boolean;
+  };
+
+  const projects = data?.projects ?? [];
+
+  return (
+    <div className="app-page space-y-6">
+      <div className="app-page-header">
+        <div>
+          <h1 className="app-page-title">Scenario Planning</h1>
+          <p className="app-page-subtitle mt-1">
+            Explore what-if staffing scenarios for any project without committing changes.
+          </p>
+        </div>
+      </div>
+
+      <div className="app-surface overflow-hidden">
+        {isLoading ? (
+          <div className="divide-y divide-gray-100 dark:divide-gray-800">
+            {Array.from({ length: 5 }).map((_, i) => (
+              <div key={i} className="flex items-center gap-4 px-4 py-3">
+                <div className="h-4 w-20 shimmer-skeleton rounded" />
+                <div className="h-4 flex-1 shimmer-skeleton rounded" />
+                <div className="h-4 w-24 shimmer-skeleton rounded" />
+              </div>
+            ))}
+          </div>
+        ) : projects.length === 0 ? (
+          <EmptyState
+            title="No projects yet"
+            detail="Create a project first, then return here to plan scenarios."
+            action={{ label: "Go to Projects", onClick: () => { window.location.href = "/projects"; } }}
+          />
+        ) : (
+          <table className="w-full text-sm">
+            <thead>
+              <tr className="border-b border-gray-100 dark:border-gray-800 text-xs font-medium text-gray-500 dark:text-gray-400 uppercase tracking-wide">
+                <th className="px-4 py-3 text-left">Code</th>
+                <th className="px-4 py-3 text-left">Project</th>
+                <th className="px-4 py-3 text-left">Client</th>
+                <th className="px-4 py-3 text-left">Status</th>
+                <th className="px-4 py-3 text-left">Start</th>
+                <th className="px-4 py-3 text-left">End</th>
+                <th className="px-4 py-3" />
+              </tr>
+            </thead>
+            <tbody className="divide-y divide-gray-50 dark:divide-gray-800/50">
+              {projects.map((p) => (
+                <tr
+                  key={p.id}
+                  className="group hover:bg-gray-50 dark:hover:bg-gray-800/30 transition-colors"
+                >
+                  <td className="px-4 py-3 font-mono text-xs text-gray-500 dark:text-gray-400">
+                    {p.shortCode}
+                  </td>
+                  <td className="px-4 py-3 font-medium text-gray-900 dark:text-gray-100">
+                    {p.name}
+                  </td>
+                  <td className="px-4 py-3 text-gray-500 dark:text-gray-400">
+                    {p.clientId ?? "—"}
+                  </td>
+                  <td className="px-4 py-3">
+                    <span className={`inline-flex items-center rounded-full px-2 py-0.5 text-xs font-medium ${PROJECT_STATUS_BADGE[p.status] ?? PROJECT_STATUS_BADGE["DRAFT"]}`}>
+                      {p.status.charAt(0) + p.status.slice(1).toLowerCase().replace("_", " ")}
+                    </span>
+                  </td>
+                  <td className="px-4 py-3 text-gray-500 dark:text-gray-400 tabular-nums">
+                    {p.startDate ? formatDate(new Date(p.startDate)) : "—"}
+                  </td>
+                  <td className="px-4 py-3 text-gray-500 dark:text-gray-400 tabular-nums">
+                    {p.endDate ? formatDate(new Date(p.endDate)) : "—"}
+                  </td>
+                  <td className="px-4 py-3 text-right">
+                    <Link
+                      href={`/projects/${p.id}/scenario`}
+                      className="inline-flex items-center gap-1 rounded-lg border border-gray-200 dark:border-gray-700 px-3 py-1 text-xs font-medium text-gray-600 dark:text-gray-300 opacity-0 group-hover:opacity-100 transition hover:border-gray-400 hover:bg-gray-50 dark:hover:bg-gray-800"
+                    >
+                      Open Scenario
+                      <svg className="h-3 w-3" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                        <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M9 5l7 7-7 7" />
+                      </svg>
+                    </Link>
+                  </td>
+                </tr>
+              ))}
+            </tbody>
+          </table>
+        )}
+      </div>
+    </div>
+  );
+}

apps/web/src/components/ui/DateRangePresets.tsx

@@ -0,0 +1,59 @@
+"use client";
+
+interface DateRangePresetsProps {
+  onSelect: (start: string, end: string) => void;
+  className?: string;
+}
+
+function toIso(d: Date): string {
+  return d.toISOString().slice(0, 10);
+}
+
+function getPresets(): { label: string; start: string; end: string }[] {
+  const now = new Date();
+  const y = now.getFullYear();
+  const m = now.getMonth(); // 0-based
+
+  // This month
+  const monthStart = new Date(y, m, 1);
+  const monthEnd = new Date(y, m + 1, 0);
+
+  // This quarter
+  const q = Math.floor(m / 3);
+  const quarterStart = new Date(y, q * 3, 1);
+  const quarterEnd = new Date(y, q * 3 + 3, 0);
+
+  // Next 3 months
+  const next3Start = new Date(now.getFullYear(), now.getMonth(), now.getDate());
+  const next3End = new Date(now.getFullYear(), now.getMonth() + 3, now.getDate() - 1);
+
+  // This year
+  const yearStart = new Date(y, 0, 1);
+  const yearEnd = new Date(y, 11, 31);
+
+  return [
+    { label: "This month", start: toIso(monthStart), end: toIso(monthEnd) },
+    { label: "This quarter", start: toIso(quarterStart), end: toIso(quarterEnd) },
+    { label: "Next 3 months", start: toIso(next3Start), end: toIso(next3End) },
+    { label: "This year", start: toIso(yearStart), end: toIso(yearEnd) },
+  ];
+}
+
+export function DateRangePresets({ onSelect, className }: DateRangePresetsProps) {
+  const presets = getPresets();
+
+  return (
+    <div className={`flex flex-wrap gap-1.5 ${className ?? ""}`}>
+      {presets.map((p) => (
+        <button
+          key={p.label}
+          type="button"
+          onClick={() => onSelect(p.start, p.end)}
+          className="rounded-full border border-gray-200 bg-white px-2.5 py-0.5 text-xs font-medium text-gray-600 transition hover:border-gray-400 hover:bg-gray-50 dark:border-gray-700 dark:bg-gray-800 dark:text-gray-300 dark:hover:border-gray-500 dark:hover:bg-gray-700"
+        >
+          {p.label}
+        </button>
+      ))}
+    </div>
+  );
+}

apps/web/src/components/ui/EmptyState.tsx

@@ -0,0 +1,36 @@
+import type { ReactNode } from "react";
+
+interface EmptyStateProps {
+  icon?: ReactNode;
+  title: string;
+  detail?: string;
+  action?: {
+    label: string;
+    onClick: () => void;
+  };
+  testId?: string;
+}
+
+export function EmptyState({ icon, title, detail, action, testId }: EmptyStateProps) {
+  return (
+    <div
+      data-testid={testId}
+      className="flex flex-col items-center gap-2 py-12 text-center text-sm text-gray-500 dark:text-gray-400"
+    >
+      {icon && (
+        <div className="mb-1 text-gray-300 dark:text-gray-600">{icon}</div>
+      )}
+      <p className="font-medium text-gray-700 dark:text-gray-200">{title}</p>
+      {detail && <p>{detail}</p>}
+      {action && (
+        <button
+          type="button"
+          onClick={action.onClick}
+          className="mt-1 rounded-lg border border-gray-300 px-3 py-1.5 text-xs font-medium text-gray-700 transition hover:border-gray-400 hover:bg-gray-50 dark:border-gray-600 dark:text-gray-200 dark:hover:bg-gray-800"
+        >
+          {action.label}
+        </button>
+      )}
+    </div>
+  );
+}