### expert_build/cli.py
VERDICT: PASS
CORRECTNESS: VALID
SPEC_COMPLIANCE: N/A
ISSUE_COMPLIANCE: N/A
BELIEF_COMPLIANCE: CONSISTENT
TEST_COVERAGE: COVERED
INTEGRATION: WIRED
REASONING: The addition of the `--parallel` argument is straightforward and correctly integrated into the `summarize` sub-command with a sensible default value.
---

### expert_build/summarize.py
VERDICT: CONCERN
CORRECTNESS: QUESTIONABLE
SPEC_COMPLIANCE: N/A
ISSUE_COMPLIANCE: N/A
BELIEF_COMPLIANCE: CONSISTENT
TEST_COVERAGE: COVERED
INTEGRATION: WIRED
REASONING: 1. **Memory Regression**: In `_summarize_one`, `_prepare_source(source_path)` is called *before* entering the semaphore block. This means that if 1,000 files are being processed, all 1,000 files will be read into memory and converted into prompts simultaneously before any are limited by the semaphore. For large repositories, this could lead to significant memory pressure or exhaustion.
2. **Noisy UI**: The `print(f"Summarizing: {source_path.name}")` call is also before the semaphore. In a parallel run, the user will see a "thundering herd" of print statements for every file immediately, rather than seeing them as they are actually being sent to the LLM.
3. **Docstring Mismatch**: The docstring for `_prepare_source` states it returns `(content, source_url, source_id, prompt)`, but the implementation only returns 3 values: `(source_url, source_id, prompt)`.
4. **Blocking I/O**: The use of synchronous file operations (`read_text`, `write_text`, `open`) inside an `asyncio` loop blocks the event loop. While typically acceptable for CLI tools with local SSDs, it is a sub-optimal pattern for asynchronous code.

**Recommendation**: Move the `_prepare_source` call and the "Summarizing" print statement inside the `async with semaphore:` block to ensure only `parallel` files are in memory and reported at any given time.
---

### tests/test_summarize.py
VERDICT: PASS
CORRECTNESS: VALID
SPEC_COMPLIANCE: N/A
ISSUE_COMPLIANCE: N/A
BELIEF_COMPLIANCE: CONSISTENT
TEST_COVERAGE: COVERED
INTEGRATION: WIRED
REASONING: The tests have been correctly updated to accommodate the asynchronous migration of the `invoke` function. The use of `AsyncMock` is appropriate, and the new parallel execution tests provide good verification that the concurrency logic works as expected.
---

### SELF_REVIEW
LIMITATIONS: Based on the observations, I noted that `invoke_sync` is still used in several other modules (`exam.py`, `propose.py`, etc.). Since these were not included in the diff, I am assuming this PR was intentionally scoped only to the `summarize` command. I am also assuming that the project accepts blocking synchronous I/O within async functions for simplicity in CLI operations.
---

### FEATURE_REQUESTS
- It would be helpful to see the full content of `expert_build/llm.py` even if it wasn't modified, to verify the exact signature and behavior of the new `invoke` function and the remaining `invoke_sync` wrapper. (Note: This was partially addressed by the provided observations).
