Add Gradle project with Chaquopy-based Android app

Replace the python-for-android/kivy build system with a standard Gradle
project using Chaquopy for Python integration. This is the core of the
architecture migration.

Build system:
- Gradle wrapper (8.11.1), root and app build files
- Chaquopy plugin for embedding Python in the Android app
- Updated .gitignore, requirements.txt, pyproject.toml

Java application layer:
- App, WebViewActivity, KolibriWebChromeClient for WebView-based UI
- KolibriServerService/ViewModel for managing the Kolibri HTTP server
- KolibriEnvironmentSetup for Python environment configuration
- WorkController/WorkControllerService for background task orchestration
- Worker classes (BaseTaskWorker, ForegroundWorker, BackgroundWorker)
- Task management (Task, TaskWorkerImpl, WorkerImpl, Observable/Observer)
- Notification system (Builder, Manager, NotificationRef, Notifier)
- Utility classes (AuthUtils, ContextUtil, NetworkUtils, ShareUtils)

Python application layer:
- main.py entry point for Kolibri server lifecycle
- taskworker.py and task_reconciler.py for background task execution
- auth.py for authentication token generation
- Kolibri plugin and settings modules
- monkey_patch_zeroconf.py for Android compatibility

Android resources:
- WebView layout with animated splash screen
- Kolibri logo vector drawable with wing-flap animation
- Notification icons, themes, colors
- Network security config, file provider paths
- Localized HTML content for loading/error screens

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: rtibbles

.gitignore

@@ -1,44 +1,64 @@
-# A generated source file
-src/strings.py
+# Generated source files
+app/src/main/python/strings.py
+app/src/main/res/values-*/strings.xml
+
+# Temporary files
 tmpenv
-tar
-python-for-android/build/
-python-for-android/packages/**
-python-for-android/dists/kolibri/_python*
-python-for-android/dists/kolibri/.gradle
-python-for-android/dists/kolibri/build
-python-for-android/dists/kolibri/gradle/*
-python-for-android/dists/kolibri/jni
-python-for-android/dists/kolibri/libs
-python-for-android/dists/kolibri/templates
-python-for-android/dists/kolibri/obj
-python-for-android/dists/kolibri/src/res_initial
-python-for-android/dists/kolibri/src/main/assets/private.tar
-python-for-android/dists/kolibri/webview_includes
-python-for-android/dists/kolibri/*.*
-python-for-android/dists/kolibri/gradlew
-python-for-android/dists/kolibri/src/main/res/*/html_content.xml
-python-for-android/dists/kolibri/src/main/res/values-*/strings.xml
-!python-for-android/dists/kolibri/build.gradle
-!python-for-android/dists/kolibri/gradle.properties
-
-# File format for signing key
+tmphome/
+
+# Kolibri tar files and extracted source
+tar/
+tar/extracted/
+
+# File format for signing keys
 *.jks
+*.keystore
 
-# output folder
+# Output folder
 dist/
 
+# Version code file
+.version-code
+
+# Python
 __pycache__
 *.pyc
-build_docker
-bin/
-build.log
-tmphome/
-android_root/
 
+# Android build artifacts
+android_root/
 *.apk
+bin/
+build/
+.gradle/
+.cxx
+.externalNativeBuild
+captures/
+local.properties
+
+# IDE
+.idea/
+.vscode/
+*.iml
+.DS_Store
+
+# Claude Code sandbox artifacts
+.bash_profile
+.bashrc
+.profile
+.zprofile
+.zshrc
+.gitconfig
+.ripgreprc
+.mcp.json
+.claude/
+HEAD
+config
+hooks/
+objects/
+refs/
+
+# Environment
 .env
-.version-code
-*.keystore
 .envrc
-.idea/
+build_docker
+build.log