add transitions and micro-interactions across all views

- Page transitions with slide-up/fade on route changes (App.vue)
- NavRail sliding active indicator with spring-like easing
- List enter/leave/move animations on Entries, Projects, Clients, Timer
- Modal enter/leave transitions with scale+fade on all dialogs
- Dropdown transitions with overshoot on all select/picker components
- Button feedback (scale on hover/active), card hover lift effects
- Timer pulse on start, glow on stop, floating empty state icons
- Content fade-in on Dashboard, Reports, Calendar, Timesheet
- Tag chip enter/leave animations in AppTagInput
- Progress bar smooth width transitions
- Implementation plan document

src/views/CalendarView.vue

@@ -34,7 +34,8 @@
     </div>
 
     <!-- Calendar Grid -->
-    <div class="flex-1 bg-bg-surface rounded-lg border border-border-subtle overflow-hidden flex flex-col min-h-0">
+    <Transition name="fade" mode="out-in">
+    <div :key="weekStart.getTime()" class="flex-1 bg-bg-surface rounded-lg border border-border-subtle overflow-hidden flex flex-col min-h-0">
       <!-- Day column headers -->
       <div class="grid shrink-0 border-b border-border-subtle" :style="gridStyle">
         <!-- Top-left corner (hour gutter) -->
@@ -119,6 +120,7 @@
         </div>
       </div>
     </div>
+    </Transition>
   </div>
 </template>