Initial commit: HeliBoard + Gemma 4 on-device AI correction

Integrates LiteRT-LM (Google) with Gemma 4 E2B-it for on-device
spell/grammar correction in HeliBoard. After sentence-ending punctuation,
the model checks the sentence and shows a correction in the suggestion strip.
Tapping it replaces the original text — fully offline, no cloud API.

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

.gitignore

@@ -0,0 +1,26 @@
+*.iml
+.gradle/
+local.properties
+.idea/
+.DS_Store
+build/
+/captures/
+.externalNativeBuild/
+.cxx/
+*.jks
+*.keystore
+
+# Gradle wrapper jar (commit only the .properties file)
+gradle/wrapper/gradle-wrapper.jar
+gradlew
+gradlew.bat
+
+# HeliBoard sources are cloned by setup_heliboard.sh — not tracked here
+heliboard/
+
+# AI model files are too large for git — push to device via ADB
+*.litertlm
+*.task
+
+# Claude internal files
+.claude/