Add HTTP API server, Android app, and CI build/publish pipeline

- docker-compose.yml + tooling-container/src/server.py: serve
  preprocess/OCR/extract over an async job API (POST /jobs, GET
  /jobs/{id}) instead of manual host-script runs per receipt
- android/: Kotlin/Compose app - capture a receipt photo, poll job
  progress, review/edit extracted fields, save locally (Room), export
  to CSV/ODS
- .gitea/workflows/build.yml: build the debug APK and publish it to
  dl.ladkau.de on push
- build-image.sh: also pull ollama/ollama so all pipeline images are
  ready after one script
- add project logo (also used for the app's launcher icon/splash)

android/gradle.properties

@@ -0,0 +1,11 @@
+org.gradle.jvmargs=-Xmx2048m -Dfile.encoding=UTF-8
+android.useAndroidX=true
+kotlin.code.style=official
+ksp.useKSP2=true
+
+# AGP 9's built-in Kotlin support rejects KSP's use of the kotlin.sourceSets
+# DSL to register generated-source dirs (Room's annotation processor, via
+# KSP) - this is AGP/KSP's own suggested suppression, not a workaround for
+# anything we did. See https://developer.android.com/r/tools/built-in-kotlin
+android.disallowKotlinSourceSets=false
+