fix: use direct aiweb_common imports, cap JRE heap, update compose

- Change `from llm_utils.aiweb_common` to `from aiweb_common` so
  imports work both locally (via PYTHONPATH) and in Docker (pip install)
- Cap PlantUML JRE heap at 256MB (-Xmx256m) to prevent runaway memory
- Add PYTHONUNBUFFERED and UMLBOT_PLANTUML_JAR_PATH to compose
  environment, remove .env file reference
- Verified: rendering works in Docker container, 66 tests pass

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: rlmelvin

UMLBot/diagram_handlers/uml_draft_handler.py

@@ -61,7 +61,7 @@ def escape_curly_braces(val: Optional[str]) -> Optional[str]:
     return val.replace("{", "{{").replace("}", "}}")
 
 
-from llm_utils.aiweb_common.WorkflowHandler import WorkflowHandler
+from aiweb_common.WorkflowHandler import WorkflowHandler
 from UMLBot.config.config import UMLBotConfig
 
 

UMLBot/services/diagram_service.py

@@ -300,7 +300,7 @@ def _render_plantuml_jar(
     jar_path = UMLBotConfig.PLANTUML_JAR_PATH
     try:
         proc = subprocess.run(
-            ["java", "-jar", jar_path, "-tpng", "-pipe"],
+            ["java", "-Xmx256m", "-jar", jar_path, "-tpng", "-pipe"],
             input=plantuml_code.encode("utf-8"),
             capture_output=True,
             timeout=30,

docker-compose.yml

@@ -1,8 +1,9 @@
 services:
   umlbot:
     build: .
-    env_file:
-      - .env
+    environment:
+      PYTHONUNBUFFERED: 1
+      UMLBOT_PLANTUML_JAR_PATH: /opt/plantuml/plantuml.jar
     ports:
       - "8000:8000"
     healthcheck:

tests/test_generic_error_handler.py

@@ -4,7 +4,7 @@
 """
 
 import pytest
-from llm_utils.aiweb_common.generate.GenericErrorHandler import GenericErrorHandler
+from aiweb_common.generate.GenericErrorHandler import GenericErrorHandler
 
 
 def test_successful_operation():

tests/test_integration_chat_uml_error.py

@@ -11,7 +11,7 @@
 from unittest.mock import Mock
 from UMLBot.diagram_handlers.uml_draft_handler import UMLDraftHandler
 from UMLBot.config.config import UMLBotConfig
-from llm_utils.aiweb_common.generate.GenericErrorHandler import GenericErrorHandler
+from aiweb_common.generate.GenericErrorHandler import GenericErrorHandler
 
 
 class DummyPrompt: