Add Vietnamese README

Switch default README to Korean, add English and Japanese

Restore agent to plugin agents/ for team orchestration

Move agent out of plugin auto-discovery

Add namespace collision note to READMEs

Add /oracle standalone skill alongside /oracle:ask plugin

Rename repo from claude-oracle to oracle

Rename plugin to oracle, add ask skill

Remove ask-oracle skill, agent-only distribution

Add plugin manifest for Claude Code plugin system

Add backend configuration docs, symlink personal oracle

Add Korean README

Initial release: cross-model verification for Claude Code