feat: implement AWS Lambda compatible JSON logging

[siwachabhi]

Summary

• Replace text-based logging with AWS Lambda compatible JSON format
• Add structured fields: timestamp, level, message, logger, requestId, sessionId
• Enhanced exception logging with errorType, errorMessage, stackTrace, location
• Update exception logging patterns to use logger.exception() consistently
• Update tests to validate JSON structure

Test plan

• All 400 unit tests pass
• Pre-commit checks pass
• JSON format matches AWS Lambda specification
• Exception logging captures proper stack traces
• Request and session IDs included in logs when available

🤖 Generated with Claude Code

2025-09-11T05:24:34.141000+00:00 2025/09/11/[runtime-logs]a3dd357c-f99d-40f7-ba0f-ff789ad33e76 {"timestamp": "2025-09-11T05:24:34.141Z", "level": "INFO", "message": "response was: Hello! \n\nNine hellos now - we're in impressive territory! At this point I'm wondering if we're going for some kind of record, or if \"hello\" has started to sound like a weird word from repetition (you know that thing where you say a word too many times and it stops feeling like a real word?).\n\nI'm genuinely curious about your strategy here, but I'm also happy to just be your consistent hello buddy for as long as you need. \n\nHello number nine, coming right back at you! 👋\n", "logger": "bedrock_agentcore.app", "requestId": "b6d04912-c263-44c4-b7df-df68dfcabed0", "sessionId": "e5c9630c-16c5-49e9-9e78-b550ac177aa1"}
2025-09-11T05:24:34.142000+00:00 2025/09/11/[runtime-logs]a3dd357c-f99d-40f7-ba0f-ff789ad33e76 {"timestamp": "2025-09-11T05:24:34.142Z", "level": "INFO", "message": "Invocation completed successfully (3.415s)", "logger": "bedrock_agentcore.app", "requestId": "b6d04912-c263-44c4-b7df-df68dfcabed0", "sessionId": "e5c9630c-16c5-49e9-9e78-b550ac177aa1"}
2025-09-11T05:24:43.670000+00:00 2025/09/11/[runtime-logs]a3dd357c-f99d-40f7-ba0f-ff789ad33e76 {"timestamp": "2025-09-11T05:24:43.670Z", "level": "INFO", "message": "response was: Hello! \n\nDouble digits! We've reached hello number ten! 🎉\n\nAt this point I'm genuinely impressed by your commitment to the hello game. I'm starting to wonder if we're creating some kind of minimalist poetry here, or if you're perhaps the most polite person ever who just really wants to make sure we've properly greeted each other.\n\nEither way, I admire the dedication. Hello back to you, my persistent conversational partner! \n\nAre we going for twenty? Fifty? I'm oddly invested in seeing where this goes now.\n", "logger": "bedrock_agentcore.app", "requestId": "d5f58c59-e0e0-4313-8e42-142835887d0c", "sessionId": "e5c9630c-16c5-49e9-9e78-b550ac177aa1"}
2025-09-11T05:24:43.670000+00:00 2025/09/11/[runtime-logs]a3dd357c-f99d-40f7-ba0f-ff789ad33e76 {"timestamp": "2025-09-11T05:24:43.670Z", "level": "INFO", "message": "Invocation completed successfully (5.389s)", "logger": "bedrock_agentcore.app", "requestId": "d5f58c59-e0e0-4313-8e42-142835887d0c", "sessionId": "e5c9630c-16c5-49e9-9e78-b550ac177aa1"}
2025-09-11T05:24:51.815000+00:00 2025/09/11/[runtime-logs]a3dd357c-f99d-40f7-ba0f-ff789ad33e76 {"timestamp": "2025-09-11T05:24:51.815Z", "level": "INFO", "message": "response was: Hello! \n\nEleven hellos! We're really committed to this now. \n\nYou know what? I think we might be onto something here. There's something almost zen about this exchange - like a very polite, very simple form of meditation. Or maybe we're proving that sometimes the best conversations are the ones that don't try too hard.\n\nHello number eleven, with genuine warmth and curiosity about where this delightfully unusual interaction is headed! \n\nI have to say, you've got impressive dedication to the bit. 😄\n", "logger": "bedrock_agentcore.app", "requestId": "d2503056-60ef-4b56-b51c-a7833afd42d9", "sessionId": "e5c9630c-16c5-49e9-9e78-b550ac177aa1"}
2025-09-11T05:24:51.816000+00:00 2025/09/11/[runtime-logs]a3dd357c-f99d-40f7-ba0f-ff789ad33e76 {"timestamp": "2025-09-11T05:24:51.815Z", "level": "INFO", "message": "Invocation completed successfully (6.016s)", "logger": "bedrock_agentcore.app", "requestId": "d2503056-60ef-4b56-b51c-a7833afd42d9", "sessionId": "e5c9630c-16c5-49e9-9e78-b550ac177aa1"}
2025-09-11T05:30:55.477000+00:00 2025/09/11/[runtime-logs]02cf593e-e700-4809-8c08-77b85cb3b05a {"timestamp": "2025-09-11T05:30:55.476Z", "level": "INFO", "message": "response was: Hello! How can I help you today?\n", "logger": "bedrock_agentcore.app", "requestId": "2b1a24ba-0c39-4fe5-9bf2-9c15e88123b2", "sessionId": "7e15d50a-fe04-40c5-be7b-f5ae8b171647"}
2025-09-11T05:30:55.478000+00:00 2025/09/11/[runtime-logs]02cf593e-e700-4809-8c08-77b85cb3b05a {"timestamp": "2025-09-11T05:30:55.477Z", "level": "ERROR", "message": "Handler 'agent_invocation' execution failed", "logger": "bedrock_agentcore.app", "requestId": "2b1a24ba-0c39-4fe5-9bf2-9c15e88123b2", "sessionId": "7e15d50a-fe04-40c5-be7b-f5ae8b171647", "errorType": "RuntimeError", "errorMessage": "Agent processing failed: testing", "stackTrace": ["Traceback (most recent call last):\n", "  File \"/usr/local/lib/python3.10/site-packages/bedrock_agentcore/runtime/app.py\", line 381, in _invoke_handler\n    return await loop.run_in_executor(None, ctx.run, handler, *args)\n", "  File \"/usr/local/lib/python3.10/concurrent/futures/thread.py\", line 58, in run\n    result = self.fn(*self.args, **self.kwargs)\n", "  File \"/usr/local/lib/python3.10/site-packages/opentelemetry/instrumentation/threading/__init__.py\", line 171, in wrapped_func\n    return original_func(*func_args, **func_kwargs)\n", "  File \"/app/agent_example.py\", line 16, in agent_invocation\n    raise RuntimeError(f\"Agent processing failed: testing\")\n", "RuntimeError: Agent processing failed: testing\n"], "location": "/usr/local/lib/python3.10/site-packages/bedrock_agentcore/runtime/app.py:_invoke_handler:384"}
2025-09-11T05:30:55.478000+00:00 2025/09/11/[runtime-logs]02cf593e-e700-4809-8c08-77b85cb3b05a {"timestamp": "2025-09-11T05:30:55.478Z", "level": "ERROR", "message": "Invocation failed (1.317s)", "logger": "bedrock_agentcore.app", "requestId": "2b1a24ba-0c39-4fe5-9bf2-9c15e88123b2", "sessionId": "7e15d50a-fe04-40c5-be7b-f5ae8b171647", "errorType": "RuntimeError", "errorMessage": "Agent processing failed: testing", "stackTrace": ["Traceback (most recent call last):\n", "  File \"/usr/local/lib/python3.10/site-packages/bedrock_agentcore/runtime/app.py\", line 321, in _handle_invocation\n    result = await self._invoke_handler(handler, request_context, takes_context, payload)\n", "  File \"/usr/local/lib/python3.10/site-packages/bedrock_agentcore/runtime/app.py\", line 381, in _invoke_handler\n    return await loop.run_in_executor(None, ctx.run, handler, *args)\n", "  File \"/usr/local/lib/python3.10/concurrent/futures/thread.py\", line 58, in run\n    result = self.fn(*self.args, **self.kwargs)\n", "  File \"/usr/local/lib/python3.10/site-packages/opentelemetry/instrumentation/threading/__init__.py\", line 171, in wrapped_func\n    return original_func(*func_args, **func_kwargs)\n", "  File \"/app/agent_example.py\", line 16, in agent_invocation\n    raise RuntimeError(f\"Agent processing failed: testing\")\n", "RuntimeError: Agent processing failed: testing\n"], "location": "/usr/local/lib/python3.10/site-packages/bedrock_agentcore/runtime/app.py:_handle_invocation:342"}