refactor(views): extract shared TodayAction top-bar button

Collapse the today icon-button block that was copy-pasted into all four
calendar top bars (Week/Month/Day/Agenda) into one TodayAction composable in
ui/common. No behaviour change.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

app/src/main/java/de/jeanlucmakiola/calendula/ui/agenda/AgendaScreen.kt

@@ -22,7 +22,6 @@ import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.Coffee
 import androidx.compose.material.icons.filled.Menu
 import androidx.compose.material.icons.filled.Search
-import androidx.compose.material.icons.filled.Today
 import androidx.compose.material3.ButtonDefaults
 import androidx.compose.material3.Card
 import androidx.compose.material3.DrawerValue
@@ -66,6 +65,7 @@ import de.jeanlucmakiola.calendula.ui.common.agendaRangeLabel
 import de.jeanlucmakiola.floret.identity.animateItemMotion
 import de.jeanlucmakiola.calendula.ui.common.CalendarDrawer
 import de.jeanlucmakiola.calendula.ui.common.CalendarFabColumn
+import de.jeanlucmakiola.calendula.ui.common.TodayAction
 import de.jeanlucmakiola.calendula.ui.common.CalendarFailure
 import de.jeanlucmakiola.calendula.ui.common.CalendarView
 import de.jeanlucmakiola.calendula.ui.common.IMPLEMENTED_VIEWS
@@ -528,14 +528,7 @@ private fun AgendaTopBar(
             }
         },
         actions = {
-            if (showTodayButton) {
-                IconButton(onClick = onToday) {
-                    Icon(
-                        imageVector = Icons.Default.Today,
-                        contentDescription = stringResource(R.string.today_jump_action),
-                    )
-                }
-            }
+            TodayAction(show = showTodayButton, onToday = onToday)
             IconButton(onClick = onOpenSearch) {
                 Icon(
                     imageVector = Icons.Default.Search,

app/src/main/java/de/jeanlucmakiola/calendula/ui/common/TodayAction.kt

@@ -0,0 +1,26 @@
+package de.jeanlucmakiola.calendula.ui.common
+
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.Today
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.res.stringResource
+import de.jeanlucmakiola.calendula.R
+
+/**
+ * The top-bar "jump to today" icon button, shared by every calendar view's app
+ * bar (#60). Shown in place of the fade-in FAB pill when the user moves the
+ * today control into the toolbar; renders nothing when [show] is false, so it
+ * drops straight into an app bar's `actions` slot without a wrapping condition.
+ */
+@Composable
+fun TodayAction(show: Boolean, onToday: () -> Unit) {
+    if (!show) return
+    IconButton(onClick = onToday) {
+        Icon(
+            imageVector = Icons.Default.Today,
+            contentDescription = stringResource(R.string.today_jump_action),
+        )
+    }
+}

app/src/main/java/de/jeanlucmakiola/calendula/ui/day/DayScreen.kt

@@ -27,7 +27,6 @@ import androidx.compose.foundation.verticalScroll
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.Menu
 import androidx.compose.material.icons.filled.Search
-import androidx.compose.material.icons.filled.Today
 import androidx.compose.material3.Card
 import androidx.compose.material3.CardDefaults
 import androidx.compose.material3.DrawerValue
@@ -72,6 +71,7 @@ import de.jeanlucmakiola.calendula.domain.EventInstance
 import de.jeanlucmakiola.calendula.ui.common.formatCalendarTitle
 import de.jeanlucmakiola.calendula.ui.common.CalendarDrawer
 import de.jeanlucmakiola.calendula.ui.common.CalendarFabColumn
+import de.jeanlucmakiola.calendula.ui.common.TodayAction
 import de.jeanlucmakiola.calendula.ui.common.CalendarFailure
 import de.jeanlucmakiola.calendula.ui.common.CalendarView
 import de.jeanlucmakiola.calendula.ui.common.IMPLEMENTED_VIEWS
@@ -401,14 +401,7 @@ private fun DayTopBar(
             }
         },
         actions = {
-            if (showTodayButton) {
-                IconButton(onClick = onToday) {
-                    Icon(
-                        imageVector = Icons.Default.Today,
-                        contentDescription = stringResource(R.string.today_jump_action),
-                    )
-                }
-            }
+            TodayAction(show = showTodayButton, onToday = onToday)
             IconButton(onClick = onOpenSearch) {
                 Icon(
                     imageVector = Icons.Default.Search,

app/src/main/java/de/jeanlucmakiola/calendula/ui/month/MonthScreen.kt

@@ -24,7 +24,6 @@ import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.Menu
 import androidx.compose.material.icons.filled.Search
-import androidx.compose.material.icons.filled.Today
 import androidx.compose.material3.DrawerValue
 import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.Icon
@@ -68,6 +67,7 @@ import de.jeanlucmakiola.calendula.domain.hasEnded
 import de.jeanlucmakiola.calendula.ui.common.formatCalendarTitle
 import de.jeanlucmakiola.calendula.ui.common.CalendarDrawer
 import de.jeanlucmakiola.calendula.ui.common.CalendarFabColumn
+import de.jeanlucmakiola.calendula.ui.common.TodayAction
 import de.jeanlucmakiola.calendula.ui.common.CalendarFailure
 import de.jeanlucmakiola.calendula.ui.common.CalendarView
 import de.jeanlucmakiola.calendula.ui.common.IMPLEMENTED_VIEWS
@@ -333,14 +333,7 @@ private fun MonthTopBar(
             }
         },
         actions = {
-            if (showTodayButton) {
-                IconButton(onClick = onToday) {
-                    Icon(
-                        imageVector = Icons.Default.Today,
-                        contentDescription = stringResource(R.string.today_jump_action),
-                    )
-                }
-            }
+            TodayAction(show = showTodayButton, onToday = onToday)
             IconButton(onClick = onOpenSearch) {
                 Icon(
                     imageVector = Icons.Default.Search,

app/src/main/java/de/jeanlucmakiola/calendula/ui/week/WeekScreen.kt

@@ -30,7 +30,6 @@ import androidx.compose.foundation.verticalScroll
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.Menu
 import androidx.compose.material.icons.filled.Search
-import androidx.compose.material.icons.filled.Today
 import androidx.compose.material3.Card
 import androidx.compose.material3.CardDefaults
 import androidx.compose.material3.DrawerValue
@@ -81,6 +80,7 @@ import de.jeanlucmakiola.calendula.domain.hasEnded
 import de.jeanlucmakiola.calendula.ui.common.formatCalendarTitle
 import de.jeanlucmakiola.calendula.ui.common.CalendarDrawer
 import de.jeanlucmakiola.calendula.ui.common.CalendarFabColumn
+import de.jeanlucmakiola.calendula.ui.common.TodayAction
 import de.jeanlucmakiola.calendula.ui.common.CalendarFailure
 import de.jeanlucmakiola.calendula.ui.common.CalendarView
 import de.jeanlucmakiola.calendula.ui.common.IMPLEMENTED_VIEWS
@@ -434,14 +434,7 @@ private fun WeekTopBar(
             }
         },
         actions = {
-            if (showTodayButton) {
-                IconButton(onClick = onToday) {
-                    Icon(
-                        imageVector = Icons.Default.Today,
-                        contentDescription = stringResource(R.string.today_jump_action),
-                    )
-                }
-            }
+            TodayAction(show = showTodayButton, onToday = onToday)
             IconButton(onClick = onOpenSearch) {
                 Icon(
                     imageVector = Icons.Default.Search,