fix: resolve 3 UX bugs from gitlooper ticket sweep (#45 #47 #48)

- #47: Remove misleading asterisk from Budget (EUR) label in project
  wizard — budget is optional per canGoNext() logic
- #48: Parse Zod validation JSON in wizard submit error handler so users
  see "Responsible person is required" instead of raw JSON array
- #45: Expose isEntriesError from timeline query context; TimelineView
  now renders an explicit error message instead of a silent empty canvas
  when the getEntriesView query fails

Co-Authored-By: claude-flow <ruv@ruv.net>

apps/web/src/components/timeline/TimelineContext.tsx

@@ -203,6 +203,7 @@ export interface TimelineContextValue {
   // ─ Loading
   isLoading: boolean;
   isInitialLoading: boolean;
+  isEntriesError: boolean;
   totalAllocCount: number;
   activeFilterCount: number;
 
@@ -328,6 +329,7 @@ export function TimelineProvider({
   ) as {
     data: TimelineEntriesView | undefined;
     isLoading: boolean;
+    isError: boolean;
     refetch: () => Promise<unknown>;
   };
 
@@ -344,11 +346,12 @@ export function TimelineProvider({
   ) as {
     data: TimelineEntriesView | undefined;
     isLoading: boolean;
+    isError: boolean;
     refetch: () => Promise<unknown>;
   };
 
   const entriesViewQuery = isSelfServiceTimeline ? selfEntriesViewQuery : staffEntriesViewQuery;
-  const { data: entriesView, isLoading, refetch: refetchEntriesView } = entriesViewQuery;
+  const { data: entriesView, isLoading, isError: isEntriesError, refetch: refetchEntriesView } = entriesViewQuery;
 
   const assignments = entriesView?.assignments ?? [];
   const demands = entriesView?.demands ?? [];
@@ -774,6 +777,7 @@ export function TimelineProvider({
       blinkOverbookedDays,
       isLoading,
       isInitialLoading,
+      isEntriesError,
       totalAllocCount,
       activeFilterCount,
     }),
@@ -800,6 +804,7 @@ export function TimelineProvider({
       blinkOverbookedDays,
       isLoading,
       isInitialLoading,
+      isEntriesError,
       totalAllocCount,
       activeFilterCount,
     ],

apps/web/src/components/timeline/TimelineView.tsx

@@ -332,6 +332,7 @@ function TimelineViewContent({
     today,
     isLoading,
     isInitialLoading,
+    isEntriesError,
     totalAllocCount,
   } = ctx;
 
@@ -708,7 +709,11 @@ function TimelineViewContent({
         onScroll={handleContainerScroll}
         className="app-surface relative z-0 flex-1 overflow-auto"
       >
-        {isInitialLoading ? (
+        {isEntriesError ? (
+          <div className="flex flex-col items-center justify-center gap-3 py-24 text-sm text-red-600 dark:text-red-400">
+            <span>Failed to load timeline data. Please try refreshing the page.</span>
+          </div>
+        ) : isInitialLoading ? (
           <div className="flex items-center justify-center py-24 text-sm text-gray-500 dark:text-gray-400">
             Loading timeline...
           </div>