feat: add Calendar, Timesheet, and MiniTimer views

Calendar shows weekly time-block layout with hour rows, entry positioning,
current time indicator, and week navigation. Timesheet provides a weekly
grid with project/task rows, day columns, totals, and add-row functionality.
MiniTimer is a minimal always-on-top timer display for the floating window.

src/router/index.ts

@@ -28,11 +28,26 @@ const router = createRouter({
       name: 'Entries',
       component: () => import('../views/Entries.vue')
     },
+    {
+      path: '/calendar',
+      name: 'Calendar',
+      component: () => import('../views/CalendarView.vue')
+    },
+    {
+      path: '/timesheet',
+      name: 'Timesheet',
+      component: () => import('../views/TimesheetView.vue')
+    },
     {
       path: '/reports',
       name: 'Reports',
       component: () => import('../views/Reports.vue')
     },
+    {
+      path: '/mini-timer',
+      name: 'MiniTimer',
+      component: () => import('../views/MiniTimer.vue')
+    },
     {
       path: '/invoices',
       name: 'Invoices',