## Description
`parse_response_with_memory` extracts an inline `<memory>...</memory>`
block from a model response and parses its JSON:
```python
try:
data = json.loads(memory_json)
memories = data.get("memories", [])
except json.JSONDecodeError as e:
logger.warning(f"Failed to parse memory JSON: {e}")
```
The block content is fully model-controlled. `json.loads` succeeds on
any valid JSON, including a non-object such as a bare array
(`<memory>["x"]</memory>`), a string, or a number. `data.get("memories",
[])` then raises `AttributeError: 'list' object has no attribute 'get'`,
which the `except json.JSONDecodeError` does not catch, so the inline
memory path crashes on output a model can realistically produce.
## Fix
Guard the parsed value: read `memories` only when the block is a JSON
object, and accept it only when it is a list (logging and ignoring
otherwise). Malformed JSON is still handled by the existing decode
guard, and a well-formed object is unchanged. This mirrors the
non-object hardening already applied to the batch JSONL path.
## Type of Change
- [x] Bug fix (non-breaking change that fixes an issue)
- [ ] New feature (non-breaking change that adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to change)
- [ ] Documentation update
- [ ] Performance improvement
- [ ] Code refactoring (no functional changes)
## Changes Made
- `headroom/memory/inline_extractor.py`: only read `memories` from a
dict-typed parsed block, and only when the field is a list; log and
ignore other shapes.
- `tests/test_memory_wrapper.py`: regression covering a non-object
memory block, a non-list `memories` field, malformed JSON, and a
well-formed block.
## Testing
- [x] Unit tests pass (`pytest`)
- [x] Linting passes (`ruff check .`)
- [x] Type checking passes (`mypy headroom`)
- [x] New tests added for new functionality
- [ ] Manual testing performed
### Test Output
```text
$ python -m pytest tests/test_memory_wrapper.py -q
6 passed
# with the fix reverted, the new test fails with
# AttributeError: 'list' object has no attribute 'get'
$ uvx ruff@0.15.17 check headroom/memory/inline_extractor.py tests/test_memory_wrapper.py
All checks passed!
$ uvx mypy@1.20.2 --ignore-missing-imports headroom/memory/inline_extractor.py
Success: no issues found in 1 source file
```
## Real Behavior Proof
- Environment: Windows 11, Python 3.12, project venv (`uv sync --extra
proxy`), `uvx ruff@0.15.17` / `uvx mypy@1.20.2`, pytest in the venv.
- Exact command / steps: called the real `parse_response_with_memory`
with a `<memory>["x"]</memory>` block, a `{"memories": "nope"}` block, a
malformed block, and a valid block; then reverted `inline_extractor.py`
and re-ran.
- Observed result: with the fix all four return cleanly (empty memories
for the bad shapes, the parsed list for the valid one) and the memory
block is still stripped from the content; with the fix reverted the
non-object block raises `AttributeError: 'list' object has no attribute
'get'`. Ran against the actual module.
- Not tested: a live end-to-end chat where a model emits a non-object
memory block.
## Review Readiness
- [x] I have performed a self-review
- [x] This PR is ready for human review
## Checklist
- [x] My code follows the project's style guidelines
- [x] I have performed a self-review of my code
- [x] I have commented my code, particularly in hard-to-understand areas
- [ ] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [x] I have added tests that prove my fix is effective or that my
feature works
- [x] New and existing unit tests pass locally with my changes
- [ ] I have updated the CHANGELOG.md if applicable
