feat(opencode): add search to auth logout command

[rekram1-node]

Summary

• make the auth logout provider picker searchable
• accept a configured provider ID or display name as a positional argument
• update CLI help snapshots for the new argument

Testing

• bun test test/cli/help/help-snapshots.test.ts -u
• exercised opencode auth logout openai and opencode auth logout OpenAI with isolated credentials
• git diff --check