Draw core-time from floret-kit (TimeBridge) via submodule + composite build

Phase 1 of the shared-kit plan: Calendula becomes the second core-time consumer.
floret-kit is embedded as a git submodule and wired with includeBuild, so the
app depends on de.jeanlucmakiola.floret:core-time and Gradle substitutes the
local source module (built from source).

- Remove the app's TimeBridge (Instant <-> epoch millis) + its test; the helpers
  now live in core-time. Repoint the 7 call sites to de.jeanlucmakiola.floret.time.
- Calendula's richer time formatting (TimeFormat, 24h CompositionLocal) stays
  app-local by design.

Reproducible-build handling (Calendula publishes via official F-Droid repro):
- Pin the submodule to a foojay-free kit commit (the resolver would let a build
  fetch a JDK -> non-reproducible; the kit never used a toolchain block).
- Harden scripts/check_reproducible_release.sh to scan the included build's
  Gradle scripts for the toolchain-resolver invariant.
- Draft fdroiddata recipe: submodules: true (else F-Droid checks out an empty
  floret-kit/ and the from-source build fails).
- CI build checkouts fetch submodules recursively.

Clean composite build + unit tests + lintDebug + repro guard all green.

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

.gitea/workflows/ci.yaml

@@ -26,6 +26,8 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v4
+          with:
+            submodules: recursive
         with:
           # Full history so the base..HEAD diff below has a merge-base.
           fetch-depth: 0

.gitea/workflows/release.yaml

@@ -33,6 +33,8 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v4
+          with:
+            submodules: recursive
 
       - name: Resolve version and whether it is a new release
         id: v
@@ -82,6 +84,8 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v4
+          with:
+            submodules: recursive
 
       - name: Setup Java
         uses: actions/setup-java@v4

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "floret-kit"]
+	path = floret-kit
+	url = https://gitea.jeanlucmakiola.de/makiolaj/floret-kit.git

app/build.gradle.kts

@@ -159,6 +159,7 @@ dependencies {
     implementation(libs.androidx.glance.material3)
 
     implementation(libs.kotlinx.datetime)
+    implementation("de.jeanlucmakiola.floret:core-time")
     implementation(libs.kotlinx.coroutines.core)
 
     debugImplementation(libs.androidx.ui.tooling)

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

@@ -1,5 +1,7 @@
 package de.jeanlucmakiola.calendula.data.calendar
 
+import de.jeanlucmakiola.floret.time.toEpochMillis
+import de.jeanlucmakiola.floret.time.toKotlinInstantFromEpochMillis
 import android.Manifest
 import android.content.ContentResolver
 import android.content.ContentUris

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

@@ -1,5 +1,6 @@
 package de.jeanlucmakiola.calendula.data.calendar
 
+import de.jeanlucmakiola.floret.time.toEpochMillis
 import de.jeanlucmakiola.calendula.data.di.IoDispatcher
 import de.jeanlucmakiola.calendula.data.prefs.CalendarPrefs
 import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs

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

@@ -1,5 +1,6 @@
 package de.jeanlucmakiola.calendula.data.calendar
 
+import de.jeanlucmakiola.floret.time.toKotlinInstantFromEpochMillis
 import android.provider.CalendarContract
 import android.util.Log
 import de.jeanlucmakiola.calendula.domain.AccessLevel

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

@@ -1,5 +1,6 @@
 package de.jeanlucmakiola.calendula.data.calendar
 
+import de.jeanlucmakiola.floret.time.toKotlinInstantFromEpochMillis
 import de.jeanlucmakiola.calendula.domain.EventStatus
 import de.jeanlucmakiola.calendula.domain.ics.IcsEvent
 import de.jeanlucmakiola.calendula.domain.ics.deriveIcsUid

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

@@ -1,5 +1,6 @@
 package de.jeanlucmakiola.calendula.data.calendar
 
+import de.jeanlucmakiola.floret.time.toKotlinInstantFromEpochMillis
 import android.util.Log
 import de.jeanlucmakiola.calendula.domain.EventInstance
 

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

@@ -1,5 +1,6 @@
 package de.jeanlucmakiola.calendula.data.calendar
 
+import de.jeanlucmakiola.floret.time.toKotlinInstantFromEpochMillis
 import de.jeanlucmakiola.calendula.domain.EventInstance
 import de.jeanlucmakiola.calendula.domain.ics.parseRfc2445DurationMillis
 

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

@@ -1,7 +0,0 @@
-package de.jeanlucmakiola.calendula.data.calendar
-
-import kotlin.time.Instant
-
-fun Long.toKotlinInstantFromEpochMillis(): Instant = Instant.fromEpochMilliseconds(this)
-
-fun Instant.toEpochMillis(): Long = toEpochMilliseconds()

app/src/test/java/de/jeanlucmakiola/calendula/data/calendar/TimeBridgeTest.kt

@@ -1,26 +0,0 @@
-package de.jeanlucmakiola.calendula.data.calendar
-
-import com.google.common.truth.Truth.assertThat
-import kotlin.time.Instant
-import org.junit.jupiter.api.Test
-
-class TimeBridgeTest {
-
-    @Test
-    fun `epoch millis round-trips through Instant`() {
-        val original = 1_717_840_800_000L // 2024-06-08T10:00:00Z
-        val instant = original.toKotlinInstantFromEpochMillis()
-        assertThat(instant.toEpochMillis()).isEqualTo(original)
-    }
-
-    @Test
-    fun `zero millis maps to Instant epoch`() {
-        assertThat(0L.toKotlinInstantFromEpochMillis()).isEqualTo(Instant.fromEpochMilliseconds(0L))
-    }
-
-    @Test
-    fun `negative epoch millis is supported`() {
-        val original = -1_000_000L
-        assertThat(original.toKotlinInstantFromEpochMillis().toEpochMillis()).isEqualTo(original)
-    }
-}

docs/fdroid-official/de.jeanlucmakiola.calendula.yml

@@ -43,11 +43,21 @@ Builds:
     versionCode: 20705
     commit: v2.7.5
     subdir: app
+    submodules: true
     gradle:
       - yes
     # No NDK / no flavors. The release buildType applies a signingConfig only
     # when key.properties exists; on the buildserver it does not, so this
     # produces the unsigned APK F-Droid compares against our binary.
+    #
+    # submodules: true — REQUIRED from v2.11.0 onward, where the build pulls
+    # shared code from the `floret-kit` git submodule via a Gradle composite
+    # build (`includeBuild("floret-kit")`). Without it F-Droid checks out an
+    # empty floret-kit/ and the from-source build fails, stalling publishing.
+    # Inert for v2.7.5 (no submodule yet); kept here so AutoUpdateMode copies it
+    # onto every auto-generated future build entry. The kit is plain-Kotlin and
+    # carries no foojay toolchain resolver, so it clears the same reproducibility
+    # bar (enforced by scripts/check_reproducible_release.sh).
 
 # SHA-256 of our app signing certificate (public; embedded in every published
 # APK). Locks F-Droid to publish only binaries signed with our key.

scripts/check_reproducible_release.sh

@@ -34,8 +34,15 @@ else
 fi
 
 # 2. The foojay toolchain resolver must not be present in any Gradle script.
+#    This includes the floret-kit submodule: it's an included build (composite
+#    build via `includeBuild`), so F-Droid evaluates its Gradle scripts too when
+#    building from source — the same offline-scanner bar applies to it.
 gradle_files=("$SETTINGS" "$APP")
 [ -f build.gradle.kts ] && gradle_files+=(build.gradle.kts)
+if [ -d floret-kit ]; then
+  while IFS= read -r f; do gradle_files+=("$f"); done \
+    < <(find floret-kit -name '*.gradle.kts' -not -path '*/build/*')
+fi
 if grep -qi 'foojay' "${gradle_files[@]}"; then
   echo "ERROR: foojay toolchain resolver found in: $(grep -li foojay "${gradle_files[@]}" | tr '\n' ' ')" >&2
   echo "       F-Droid's source scanner rejects org.gradle.toolchains.foojay-resolver" >&2

settings.gradle.kts

@@ -22,3 +22,4 @@ dependencyResolutionManagement {
 
 rootProject.name = "Calendula"
 include(":app")
+includeBuild("floret-kit")