fix(frontend) : fix time-tracking page scroll with fixed header and filters

Restructure time-tracking page layout so the page title and filters
stay fixed while only the calendar grid body scrolls internally.

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

frontend/components/time-tracking/TimeTrackingCalendar.vue

@@ -1,9 +1,8 @@
 <template>
-    <div ref="calendarEl" class="relative rounded-lg border border-neutral-200 bg-white">
+    <div ref="calendarEl" class="relative flex h-full flex-col rounded-lg border border-neutral-200 bg-white">
         <!-- Day headers -->
         <div
-            class="sticky z-20 flex border-b border-neutral-200 bg-white"
-            :style="{ top: `${stickyOffset}px` }"
+            class="z-20 flex flex-shrink-0 border-b border-neutral-200 bg-white rounded-t-lg"
         >
             <div class="w-16 shrink-0 border-r border-neutral-200" />
             <div
@@ -22,7 +21,7 @@
         </div>
 
         <!-- Grid body -->
-        <div ref="gridBodyEl" class="relative flex">
+        <div ref="gridBodyEl" class="relative flex min-h-0 flex-1 overflow-y-auto">
             <!-- Hour labels -->
             <div class="w-16 shrink-0">
                 <div

frontend/pages/time-tracking.vue

@@ -1,6 +1,6 @@
 <template>
-    <div>
-        <div ref="pageHeaderEl" class="sticky top-0 z-40 bg-white pb-4">
+    <div class="flex min-h-0 flex-1 flex-col">
+        <div ref="pageHeaderEl" class="flex-shrink-0 pb-4">
             <div class="flex items-center justify-between">
                 <h1 class="text-2xl font-bold text-primary-500">Suivi des temps</h1>
                 <button
@@ -37,7 +37,7 @@
                 <MalioSelect
                     v-model="selectedUserId"
                     :options="userOptions"
-                min-width="!w-40"
+                    min-width="!w-44"
                     text-field="text-sm"
                     text-value="text-sm"
                     label="User"
@@ -49,7 +49,7 @@
                     :options="projectOptions"
                     empty-option-label="Tous"
                     label="Projet"
-                min-width="!w-40"
+                    min-width="!w-44"
                     text-field="text-sm"
                     text-value="text-sm"
                 />
@@ -59,14 +59,14 @@
                     :options="tagOptions"
                     empty-option-label="Tous"
                     label="Tag"
-                min-width="!w-40"
+                    min-width="!w-44"
                     text-field="text-sm"
                     text-value="text-sm"
                 />
             </div>
         </div>
 
-        <div class="mt-4">
+        <div class="mt-4 -mb-24 min-h-0 flex-1">
             <TimeEntryList
                 v-if="viewMode === 'list'"
                 :entries="filteredEntries"