docs(track): result_migration_review_pass decisions for src/rag_engine.py INTERNAL_RETHROW (2 PATTERN_1/2 + 2 compliant + 0 migration-target; noted audit script bug)

docs/reports/RESULT_MIGRATION_REVIEW_PASS_20260617.md

@@ -153,7 +153,20 @@ Other audit findings (unchanged by this review pass):
 
 ### 2.8 `src/rag_engine.py` — INTERNAL_RETHROW sites (4, baseline)
 
-*(filled in Task 3.2)*
+| Line | Context | Snippet | Decision | Pattern / Rationale |
+|---|---|---|---|---|
+| 29 | `_get_sentence_transformers` (lazy import) | `except ModuleNotFoundError as e:` (start of except) | **PATTERN_1** (composite) | The except body contains both a `raise ImportError(LOCAL_RAG_INSTALL_HINT) from e` (PATTERN_1: catch + convert + raise with better message) and a bare `raise` (PATTERN_2: re-raise original). The except itself is the boundary |
+| 36 | `_get_sentence_transformers` (lazy import) | `raise e` after `sys.stderr.write(...)` | **PATTERN_2** | Catch + log + re-raise: writes to stderr, then re-raises the original exception. The log is for observability; the re-raise preserves the traceback for the caller |
+| 57 | `BaseEmbeddingProvider.embed` (abstract method) | `raise NotImplementedError()` | **compliant** | Abstract method pattern: the base class raises `NotImplementedError` to signal subclasses must implement. The audit script's `_classify_raise` heuristic misses this (the function is not `__init__` and `NotImplementedError` doesn't match the `AssertionError, ValueError, or assert` check) |
+| 75 | `GeminiEmbeddingProvider.embed` (validation) | `raise ImportError("google-genai is not installed")` after `if google_module is None` | **compliant** | Validation raise: if a required dependency is missing, raise with an actionable message. This is the "explicit precondition check" pattern (per styleguide's "Constructors that fail with programmer errors" guidance) |
+
+**Subtotals:** 2 PATTERN_1/2 + 2 compliant + 0 migration-target.
+
+**Note (audit script bug, OUT OF SCOPE for this review pass):** The audit script's `visit_Try` method has a bug — it iterates over `node.handlers` for adding findings but then visits children of only the LAST handler's body. This causes it to miss `raise` statements in the first except handler. The `raise ImportError(LOCAL_RAG_INSTALL_HINT) from e` at L31 (in the first `except ModuleNotFoundError`) is a legitimate PATTERN_1 site that the audit misses. Document for future audit script fix.
+
+**New heuristic candidates:**
+- `raise NotImplementedError()` as the entire function body → `INTERNAL_PROGRAMMER_RAISE` (abstract method pattern; the current heuristic checks `__init__` but should also check the function is the entire body)
+- `if <var> is None: raise ImportError(...)` or similar validation raise → `INTERNAL_PROGRAMMER_RAISE` (precondition check pattern)
 
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