feat(rooms): expose authoritative member views

[tcballard]

Summary

• add strict room-members RELAY GROUP IPC and CLI queries plus /room-members in the TUI
• derive observed participants from the union of authenticated relay-published 39002 state and reduced moderation membership
• expose relay-admin state, role labels, moderation author, source event, and update time
• mark the result relay-policy-only and relay-published-may-be-partial
• update room summary counts to include authenticated published rosters
• package the command in man pages and shell completions

Security boundary

Role names and member/admin presentation never grant client-side capabilities. NIP-29 relay policy remains authoritative, and the response explicitly avoids claiming its observed set is a complete ACL.

Validation

• complete portable repository gate passed
• strict IPC, CLI, TUI, daemon room, workspace, and rustdoc tests passed
• warning-as-error clippy passed
• relay29 black-box lifecycle and Rust capture replay passed: 20 accepted, 0 refused
• packaging and cargo deny --locked check passed
• release aggregate: 4,149,856 bytes / 10 MiB

The exact Linux workspace, including omachat-mesh, is delegated to repository Ubuntu CI.