refactor(exceptions): add ruff BLE001; convert 103 broad except Exception

Per CONVENTIONS.md Part 2 ("Never bare except") and CONVENTIONS.md
Part 7 (pre-commit hooks: ruff), blind `except Exception` is now a
lint failure. Pre-existing sites are marked `# noqa: BLE001` for
later manual review; new code must use specific exception types.

Changes:
- pyproject.toml: added "BLE" to ruff lint select. BLE001 is now enforced
- 103 of 166 `except Exception` sites were auto-converted to specific
  types based on context (httpx, json, OSError, subprocess, etc.)
- 62 remaining sites marked with `# noqa: BLE001` for later review
  (mostly generic try/except wrappers that legitimately need broad catch
  for graceful degradation: e.g. compliance LLM fallback must catch
  any error to preserve the regex result)
- 1 manual fix: reverted compliance.py LLM fallback to broad except
  with explicit "must catch all errors" comment + noqa
- 2 files (commerce_sync.py, crm_sync.py) needed `import httpx` added
  so the auto-converted exception references would resolve
- 5 source files (agency, monitor, pipelines, auth_connector,
  llm_providers/registry) renamed "name" -> "<scope>_name" in
  extra={...} dicts because "name" is a reserved LogRecord field

Test impact:
- 14 failing tests -> 1 (the SSE subprocess test is a sandbox limitation,
  pre-existing and unrelated)
- New `test_ble_temp.py` verifies BLE001 catches new violations

Follow-up:
- Each `# noqa: BLE001` site should be reviewed and replaced with a
  specific exception type where possible. The most common legitimate
  broad-catch case is the LLM fallback path; everything else probably
  can be narrowed.

extraction.py

@@ -92,7 +92,7 @@ class JsonCssExtractionStrategy:
                 else:
                     text = self._get_text(element, selector)
                     row[name] = self._apply_transform(text, transform)
-            except Exception as e:
+            except Exception as e:  # noqa: BLE001
                 logger.warning("field_extract_failed", extra={"field": name, "error": str(e)})
                 row[name] = None
 
@@ -256,7 +256,7 @@ def compute_embedding(text: str, model: str = "all-MiniLM-L6-v2") -> list[float]
             return list(body.get("embedding", []))
 
         return anyio.run(_fetch)
-    except Exception:
+    except (httpx.HTTPError, httpx.RequestError):
         ngrams: dict[str, float] = {}
         for i in range(len(text) - 2):
             ng = text[i : i + 3].lower()
@@ -276,7 +276,7 @@ def filter_chunks_by_query(chunks: list[str], query: str, top_k: int = 5) -> lis
             scored.append((sim, c))
         scored.sort(key=lambda x: x[0], reverse=True)
         return [c for _, c in scored[:top_k]]
-    except Exception:
+    except Exception:  # noqa: BLE001
         logger.warning("embedding_filter_failed, returning top chunks by length")
         return sorted(chunks, key=len, reverse=True)[:top_k]