feat: Introduce .repomixignore for repomix-specific exclusions and update .gitignore to include release-manifest.json.

.gitignore

@@ -36,4 +36,5 @@ tmp
 deploy-*.sh
 
 docs/technical-diaries
-plans
+plans
+release-manifest.json

.repomixignore

@@ -0,0 +1,22 @@
+docs/*
+plans/*
+assets/*
+dist/*
+coverage/*
+build/*
+ios/*
+android/*
+tests/*
+__tests__/*
+__pycache__/*
+node_modules/*
+
+.opencode/*
+.claude/*
+.serena/*
+.pnpm-store/*
+.github/*
+.dart_tool/*
+.idea/*
+.husky/*
+.venv/*