Implement Textual TUI for Matrix rooms, threads, agents, approvals, workrooms, context, graphs, and evidence

[mdheller]

Agent work order

@copilot @codex please implement this after PR #1 lands or by branching from main after the seed merge.

Goal

Build the first real terminal UI surface for AgentTerm so it behaves like a Matrix-first Slack-term-class operator console, not only a command parser.

Required scope

• Add Textual-based TUI entry point behind an optional dependency.
• Show Matrix rooms/channels, selected thread, local event log, and command input.
• Include panes or modes for agents, Agent Registry status/grants, Policy Fabric approvals, workrooms, topics, memory/context, New Hope semantic objects, Holmes/Sherlock investigation references, MeshRush graph events, cloudshell/AgentPlane evidence, and GitHub/CI status.
• Keep side-effecting commands behind approval affordances.
• Show unresolved/denied/revoked/expired states visibly.
• Add tests around rendering/data-model transformation where feasible without requiring a real terminal session in CI.

Non-goals

• Do not bypass Matrix, Agent Registry, or Policy Fabric.
• Do not wire live SDKs directly into the TUI layer.
• Do not turn the TUI into a generic chatbot UI.

Validation

ruff check .
pytest