fix: Add PYTHONUNBUFFERED and increase test wait time for Docker logs

- Add PYTHONUNBUFFERED=1 to Dockerfile environment variables to disable
  Python's stdout/stderr buffering in containers
- Increase test wait time from 2 to 5 seconds to allow logs to be written
  before checking them in test_docker_stdio_transport and
  test_docker_http_transport
- This fixes the issue where Docker containers were running successfully
  but logs weren't visible immediately due to Python output buffering

All Docker installation tests now pass locally.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

Author: cdcore09

Dockerfile

@@ -73,7 +73,8 @@ ENV HOLOVIZ_MCP_TRANSPORT=stdio \
     HOLOVIZ_MCP_HOST=0.0.0.0 \
     HOLOVIZ_MCP_PORT=8000 \
     HOLOVIZ_MCP_LOG_LEVEL=INFO \
-    HOLOVIZ_MCP_ALLOW_CODE_EXECUTION=true
+    HOLOVIZ_MCP_ALLOW_CODE_EXECUTION=true \
+    PYTHONUNBUFFERED=1
 
 # Create entrypoint script
 RUN echo '#!/bin/bash\n\

tests/test_installation.py

@@ -99,6 +99,9 @@ def test_docker_stdio_transport(self):
             # Check container status (may have exited for stdio, which is ok)
             assert status is not None and status.stdout.strip(), f"Container {container_name} not found or not ready after {max_wait} seconds"
 
+            # Wait a moment for the application to start and write logs
+            time.sleep(5)
+
             # Check logs for successful startup (container may exit with stdio transport, that's expected)
             logs = subprocess.run(
                 ["docker", "logs", container_name],
@@ -184,6 +187,9 @@ def test_docker_http_transport(self):
             )
             assert status.stdout.strip(), f"Container {container_name} is not running"
 
+            # Wait a moment for the application to start and write logs
+            time.sleep(5)
+
             # Check logs for successful startup
             logs = subprocess.run(
                 ["docker", "logs", container_name],