feat(tui+deploy): wire TUI to live ReasoningLoop via agent_bridge; add Docker deployment

[marcuspat]

Summary

Wires the Sentinel TUI to a live ReasoningLoop via the async agent_bridge module, and adds Docker/Compose deployment artifacts.

sentinel-tui changes

agent_bridge.rs (prior commit)

• AgentConfig struct: goal, host, dry_run, backend_name, api keys, model
• run_agent_session(): async bridge that drives ReasoningLoop → SessionUpdate channel + ApprovalRequest channel

app.rs

• New fields: pending_goal, host, dry_run, session_update_rx, approval_rx, approval_responder
• start_session() sets pending_goal so the event loop can spawn the agent task on the next tick
• apply_session_update() dispatches all SessionUpdate variants to TUI state
• poll_session_updates() / poll_approval() drain channels each tick

main.rs

• run_app() event loop: drains updates, polls approval, spawns run_agent_session tokio task when pending_goal is set
• --dry-run CLI flag on tui subcommand
• Model default: claude-opus-4-8

Deployment

• Dockerfile: multi-stage rust:1.82-slim builder → debian:bookworm-slim runtime; PTY-safe binary
• docker-compose.yml: ANTHROPIC_API_KEY guard, TTY wiring (stdin_open, tty), default tui --host localhost

How to run

# Docker
ANTHROPIC_API_KEY=sk-... docker compose up

# Native
cargo run --bin sentinel -- tui --host localhost

Lifecycle

Goal input → start_session() → pending_goal set → run_app() spawns run_agent_session() → ReasoningLoop drives investigate→plan→approve→act → SessionUpdate stream updates TUI in real time