Address code review feedback: improve logging, fix redundant check, clarify docs

- Log exceptions at warning level in ConfigService (not debug)
- Include exc_info=True for startup seed failure logging
- Remove redundant `is_secret is not None` guard
- Clarify ★ markers in README environment variables docs

Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>
Agent-Logs-Url: https://github.com/christianlouis/pop_puller_to_gmail/sessions/ce88d4a8-d8c2-49b3-95a1-30592105a769

README.md

@@ -146,7 +146,7 @@ Emails are forwarded to Gmail via SMTP. This is the legacy method and is used as
 | `POP3_ACCOUNT_N_PASSWORD` | Yes | — | POP3 password |
 | `POP3_ACCOUNT_N_USE_SSL` | No | `true` | Use SSL/TLS |
 
-#### SMTP Settings ★
+#### SMTP Settings (★ database-configurable)
 
 | Variable | Required | Default | Description |
 |----------|----------|---------|-------------|
@@ -156,7 +156,7 @@ Emails are forwarded to Gmail via SMTP. This is the legacy method and is used as
 | `SMTP_PASSWORD` | For SMTP | — | SMTP password (App Password) |
 | `SMTP_USE_TLS` | No | `true` | Use STARTTLS |
 
-#### Gmail API Settings ★
+#### Gmail API Settings (★ database-configurable)
 
 | Variable | Required | Default | Description |
 |----------|----------|---------|-------------|
@@ -164,7 +164,7 @@ Emails are forwarded to Gmail via SMTP. This is the legacy method and is used as
 | `GOOGLE_CLIENT_SECRET` | For Gmail API | — | Google OAuth2 client secret |
 | `GMAIL_API_ENABLED` | No | `true` | Enable Gmail API delivery |
 
-#### Processing Settings ★
+#### Processing Settings (★ database-configurable)
 
 | Variable | Required | Default | Description |
 |----------|----------|---------|-------------|

backend/app/main.py

@@ -37,7 +37,7 @@ async def lifespan(app: FastAPI) -> AsyncIterator[None]:
         async with async_session_maker() as db:
             await ConfigService.seed_defaults(db)
     except Exception as exc:
-        logger.warning("Could not seed default settings: %s", exc)
+        logger.warning("Could not seed default settings: %s", exc, exc_info=True)
 
     yield
     # Shutdown

backend/app/services/config_service.py

@@ -190,8 +190,12 @@ class ConfigService:
                         setting.value,  # type: ignore[arg-type]
                         setting.value_type or "string",  # type: ignore[arg-type]
                     )
-            except Exception:
-                logger.debug("DB lookup failed for key=%s, falling back to env", key)
+            except Exception as exc:
+                logger.warning(
+                    "DB lookup failed for key=%s, falling back to env: %s",
+                    key,
+                    exc,
+                )
 
         env_val = os.getenv(key)
         if env_val is not None:
@@ -216,8 +220,8 @@ class ConfigService:
                         setting.value,  # type: ignore[arg-type]
                         setting.value_type or "string",  # type: ignore[arg-type]
                     )
-            except Exception:
-                logger.debug("DB bulk lookup failed, falling back to env")
+            except Exception as exc:
+                logger.warning("DB bulk lookup failed, falling back to env: %s", exc)
 
         for key in keys:
             if key not in result:
@@ -253,7 +257,6 @@ class ConfigService:
                 existing.value_type = value_type  # type: ignore[assignment]
             if description is not None:
                 existing.description = description  # type: ignore[assignment]
-            if is_secret is not None:
             existing.is_secret = is_secret  # type: ignore[assignment]
             if category is not None:
                 existing.category = category  # type: ignore[assignment]