Clean repo for open source release

Remove build artifacts, dev tool configs, unused dependencies,
and third-party source dumps. Add proper README, update .gitignore,
clean up Makefile.

.gitignore

@@ -0,0 +1,47 @@
+# Eclipse
+bin/
+*.launch
+.settings/
+.metadata/
+.classpath
+.project
+
+# IntelliJ IDEA
+out/
+*.ipr
+*.iws
+*.iml
+.idea/
+
+# Gradle
+build/
+.gradle/
+
+# Other
+eclipse/
+run/
+run-client*/
+run-data/
+node_modules/
+
+# Forge MDK
+forge*changelog.txt
+
+# Dev tools (local config)
+.claude/
+.superpowers/
+.mcp.json
+.codebase-index-cache.json
+
+# Node (not used)
+package.json
+package-lock.json
+.prettierrc.yaml
+
+# Build logs
+build_output.log
+
+# OS files
+.DS_Store
+Thumbs.db
+desktop.ini