Update time display to show fractions of days

Modify cell display and popover options to show day fractions instead of hours when in days mode, using French locale formatting.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: 55837015-10e9-4be9-b857-7f5e6be73772
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Replit-Commit-Event-Id: d7c2088e-0745-44c4-a970-ccf04e97a2dc
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Replit-Helium-Checkpoint-Created: true

artifacts/cra-app/src/pages/timesheet-detail.tsx

@@ -528,9 +528,15 @@ export default function TimesheetDetailPage() {
                       const val = localEntries[key] || 0;
                       const desc = localDescriptions[key] || "";
                       
+                      const cellDisplay = val === 0
+                        ? ""
+                        : showDays
+                          ? (val / 8).toLocaleString("fr-FR")
+                          : val;
+
                       const cellContent = (
                         <div className="relative flex items-center justify-center h-9 w-full text-xs">
-                          {val === 0 ? "" : val}
+                          {cellDisplay}
                           {desc && (
                             <span className="absolute top-0.5 right-0.5 h-1.5 w-1.5 rounded-full bg-amber-400" />
                           )}
@@ -554,6 +560,9 @@ export default function TimesheetDetailPage() {
                                 {cellContent}
                               </PopoverTrigger>
                               <PopoverContent className="w-56 p-2 space-y-2" side="bottom" align="center">
+                                <div className="text-[10px] font-semibold text-muted-foreground uppercase tracking-wide pb-1">
+                                  {showDays ? "Jour" : "Heures"}
+                                </div>
                                 <div className="grid grid-cols-5 gap-1">
                                   {HOUR_OPTIONS.map(h => (
                                     <button
@@ -568,7 +577,11 @@ export default function TimesheetDetailPage() {
                                             : "bg-muted/50 hover:bg-primary/10"
                                       )}
                                     >
-                                      {h === 0 ? "✕" : `${h}h`}
+                                      {h === 0
+                                        ? "✕"
+                                        : showDays
+                                          ? (h / 8).toLocaleString("fr-FR", { minimumFractionDigits: 3, maximumFractionDigits: 3 })
+                                          : `${h}h`}
                                     </button>
                                   ))}
                                 </div>