Add Rich token streaming: server SSE + CLI live display + CLI container

Server (agent.py):
- _stream_queues: per-session asyncio.Queue for token chunks
- _push_stream_chunk() / _end_stream() helpers
- Medium tier: astream() with <think> block filtering — real token streaming
- Light tier: full reply pushed as single chunk then [DONE]
- Complex tier: full reply pushed after agent completes then [DONE]
- GET /stream/{session_id} SSE endpoint (data: <chunk>\n\n, data: [DONE]\n\n)
- medium_model promoted to module-level global for astream() access

CLI (cli.py):
- stream_reply(): reads /stream/ SSE, renders tokens live with Rich Live (transient)
- Final reply rendered as Markdown after stream completes
- os.getlogin() replaced with os.getenv("USER") for container compatibility

Dockerfile.cli + docker-compose cli service (profiles: tools):
- Run: docker compose --profile tools run --rm -it cli

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tests/use_cases/apple_pie_research.md

@@ -13,17 +13,17 @@ curl -s -X POST http://localhost:8000/message \
   -d '{"text": "/think what is the best recipe for an apple pie?", "session_id": "use-case-apple-pie", "channel": "cli", "user_id": "claude"}'
 ```
 
-**2. Wait for the reply** via SSE (complex tier can take up to 5 minutes):
+**2. Wait for the streaming reply** (complex tier can take up to 5 minutes):
 
 ```bash
-curl -s -N --max-time 300 "http://localhost:8000/reply/use-case-apple-pie"
+curl -s -N --max-time 300 "http://localhost:8000/stream/use-case-apple-pie"
 ```
 
 **3. Confirm tier and tool usage in agent logs:**
 
 ```bash
 docker compose -f /home/alvis/adolf/docker-compose.yml logs deepagents \
-  --since=600s --no-log-prefix | grep -E "tier=complex|web_search|fetch_url|crawl4ai"
+  --since=600s | grep -E "tier=complex|web_search|fetch_url|crawl4ai"
 ```
 
 ## Evaluate (use your judgment)