refactor: Migrate package from app.lawnchair to app.autocat

[thejaustin]

Summary

The internal package structure still uses app.lawnchair as the base package. Migrating to app.autocat is the final step in the AutoCat rebrand.

Scope

• Rename all package app.lawnchair.* declarations in lawnchair/src/
• Update all import app.lawnchair.* references
• Update AndroidManifest.xml application ID and component android:name values
• Update Proguard rules, Room schemas, and resource references
• Update rootProject.name in settings.gradle

Risk Assessment

HIGH RISK — This is a large-scale change affecting hundreds of files. Requires:

• Complete find-and-replace across the codebase
• Careful handling of manifest android:name attributes
• Database schema package references (Room)
• Proto-generated class packages
• Potential backward-compatibility concerns for settings migration

Prerequisites

• refactor: Internal Class Renaming (Lawnchair -> AutoCat) #43 (Class renaming) ✅ Complete
• Stable CI build

Acceptance Criteria

• All source files use package app.autocat.*
• applicationId updated to app.autocat
• No app.lawnchair references remain in production code
• CI build passes after migration