Rename app Floret → Agendula

Floret is promoted to the family / design-language (shared-kit) name; the
tasks app itself becomes Agendula (de.jeanlucmakiola.agendula) — agenda
('things to be done') + Calendula's -ula, a twin of the Calendula name.

Renames the package, namespace, applicationId, rootProject.name, app_name,
FloretApp/FloretNavHost/FloretTransitions classes, theme, F-Droid metadata
dir, CI artifact name, and docs. The botanical word 'florets' is preserved in
the name-origin prose, which is rewritten to Agendula's etymology. Clean
build + unit tests green.

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

.gitea/workflows/release.yaml

@@ -225,7 +225,7 @@ jobs:
           if [ -z "$SAFE_REF_NAME" ]; then
             SAFE_REF_NAME="${GITHUB_SHA:-manual}"
           fi
-          cp app/build/outputs/apk/release/app-release.apk "fdroid/repo/floret_${SAFE_REF_NAME}.apk"
+          cp app/build/outputs/apk/release/app-release.apk "fdroid/repo/agendula_${SAFE_REF_NAME}.apk"
 
       - name: Copy metadata to F-Droid repo
         run: |
@@ -248,7 +248,7 @@ jobs:
           if [ ! -s /tmp/changelog.txt ]; then
             echo "See CHANGELOG.md for $VERSION." > /tmp/changelog.txt
           fi
-          CL_DIR="fdroid/metadata/de.jeanlucmakiola.floret/en-US/changelogs"
+          CL_DIR="fdroid/metadata/de.jeanlucmakiola.agendula/en-US/changelogs"
           mkdir -p "$CL_DIR"
           cp /tmp/changelog.txt "$CL_DIR/${VERSION_CODE}.txt"
           echo "Wrote $CL_DIR/${VERSION_CODE}.txt"