refactor(calendar): move the colour palette to data with named entries

AndroidSpecialDatesCalendarSpec hardcoded three ARGB literals that its KDoc
claimed were 'picked from the shared palette' — a silent-drift hazard, and
referencing ui.common from data would invert layering. The palette now lives
in data/calendar as CalendarColorPalette with named hues; the swatch pickers
use CalendarColorPalette.all and the spec references Purple/Red/Blue.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

app/src/main/java/de/jeanlucmakiola/calendula/data/calendar/CalendarColorPalette.kt

@@ -0,0 +1,22 @@
+package de.jeanlucmakiola.calendula.data.calendar
+
+/**
+ * Google-Calendar-style palette; ARGB ints for a raw `CALENDAR_COLOR` /
+ * `EVENT_COLOR`. The named entries exist for callers that need one specific
+ * hue (the managed special-dates calendars), so they can't drift from the
+ * swatches offered in the colour picker.
+ */
+object CalendarColorPalette {
+    val Red = 0xFFD50000.toInt()
+    val Orange = 0xFFE67C00.toInt()
+    val Amber = 0xFFF6BF26.toInt()
+    val Green = 0xFF33B679.toInt()
+    val DarkGreen = 0xFF0B8043.toInt()
+    val Blue = 0xFF039BE5.toInt()
+    val Indigo = 0xFF3F51B5.toInt()
+    val Purple = 0xFF8E24AA.toInt()
+    val Graphite = 0xFF616161.toInt()
+
+    /** The full palette, in swatch-row order. */
+    val all: List<Int> = listOf(Red, Orange, Amber, Green, DarkGreen, Blue, Indigo, Purple, Graphite)
+}

app/src/main/java/de/jeanlucmakiola/calendula/data/contacts/AndroidSpecialDatesCalendarSpec.kt

@@ -3,6 +3,7 @@ package de.jeanlucmakiola.calendula.data.contacts
 import android.content.Context
 import dagger.hilt.android.qualifiers.ApplicationContext
 import de.jeanlucmakiola.calendula.R
+import de.jeanlucmakiola.calendula.data.calendar.CalendarColorPalette
 import de.jeanlucmakiola.calendula.domain.contacts.SpecialDateType
 import javax.inject.Inject
 import javax.inject.Singleton
@@ -34,8 +35,8 @@ class AndroidSpecialDatesCalendarSpec @Inject constructor(
     )
 
     override fun color(type: SpecialDateType): Int = when (type) {
-        SpecialDateType.Birthday -> 0xFF8E24AA.toInt() // purple
+        SpecialDateType.Birthday -> CalendarColorPalette.Purple
-        SpecialDateType.Anniversary -> 0xFFD50000.toInt() // red
+        SpecialDateType.Anniversary -> CalendarColorPalette.Red
-        SpecialDateType.Custom -> 0xFF039BE5.toInt() // blue
+        SpecialDateType.Custom -> CalendarColorPalette.Blue
     }
 }

app/src/main/java/de/jeanlucmakiola/calendula/ui/calendars/CalendarsScreen.kt

@@ -94,7 +94,7 @@ import de.jeanlucmakiola.calendula.R
 import de.jeanlucmakiola.calendula.data.prefs.BackupStatus
 import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs
 import de.jeanlucmakiola.calendula.domain.CalendarSource
-import de.jeanlucmakiola.calendula.ui.common.CALENDAR_COLOR_PALETTE
+import de.jeanlucmakiola.calendula.data.calendar.CalendarColorPalette
 import de.jeanlucmakiola.calendula.ui.common.CalendarColorChip
 import de.jeanlucmakiola.calendula.ui.common.DialogAmountField
 import de.jeanlucmakiola.calendula.ui.common.DialogUnitDropdown
@@ -142,7 +142,7 @@ fun CalendarsScreen(
             sessionKey = editorSession,
             isNew = editorId == NEW_CALENDAR_ID,
             initialName = editing?.displayName.orEmpty(),
-            initialColor = editing?.color ?: CALENDAR_COLOR_PALETTE.first(),
+            initialColor = editing?.color ?: CalendarColorPalette.all.first(),
             initialDescription = editing?.description.orEmpty(),
             onSave = { name, color, description ->
                 val id = editorId
@@ -507,7 +507,7 @@ private fun CalendarEditor(
                 )
                 Spacer(Modifier.height(12.dp))
                 ColorSwatchRow(
-                    colors = CALENDAR_COLOR_PALETTE,
+                    colors = CalendarColorPalette.all,
                     selected = color,
                     onSelect = { color = it },
                     dark = dark,

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

@@ -67,16 +67,3 @@ fun ColorSwatchRow(
         }
     }
 }
-
-/** Google-Calendar-style palette; ARGB ints for a raw `CALENDAR_COLOR` / `EVENT_COLOR`. */
-val CALENDAR_COLOR_PALETTE: List<Int> = listOf(
-    0xFFD50000, // red
-    0xFFE67C00, // orange
-    0xFFF6BF26, // amber
-    0xFF33B679, // green
-    0xFF0B8043, // dark green
-    0xFF039BE5, // blue
-    0xFF3F51B5, // indigo
-    0xFF8E24AA, // purple
-    0xFF616161, // graphite
-).map { it.toInt() }

app/src/main/java/de/jeanlucmakiola/calendula/ui/edit/EventEditScreen.kt

@@ -119,7 +119,7 @@ import de.jeanlucmakiola.calendula.domain.toRRule
 import de.jeanlucmakiola.calendula.ui.common.calendarCollapseExit
 import de.jeanlucmakiola.calendula.ui.common.calendarExpandEnter
 import de.jeanlucmakiola.calendula.ui.common.predictiveBack
-import de.jeanlucmakiola.calendula.ui.common.CALENDAR_COLOR_PALETTE
+import de.jeanlucmakiola.calendula.data.calendar.CalendarColorPalette
 import de.jeanlucmakiola.calendula.ui.common.CalendarDatePickerDialog
 import de.jeanlucmakiola.calendula.ui.common.ColorSwatchRow
 import de.jeanlucmakiola.calendula.ui.common.DialogAmountField
@@ -1745,7 +1745,7 @@ private fun ColorPickerDialog(
                     )
                 } else {
                     ColorSwatchRow(
-                        colors = CALENDAR_COLOR_PALETTE,
+                        colors = CalendarColorPalette.all,
                         selected = selected,
                         onSelect = onPickRaw,
                         dark = dark,