Add project metadata and Gradle wrapper

- PLAN.md: architecture design document
- .idea/: Android Studio project configuration
- Gradle wrapper: v9.4.1 with daemon JVM properties

Co-Authored-By: Claude Opus 4.6 (1M context)

Signed-off-by: Avinal Kumar <avinal.xlvii@gmail.com>

gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,9 @@
+#Thu May 14 14:55:35 IST 2026
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionSha256Sum=2ab2958f2a1e51120c326cad6f385153bb11ee93b3c216c5fccebfdfbb7ec6cb
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.4.1-bin.zip
+networkTimeout=10000
+validateDistributionUrl=true
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists