Simplify email subject handling and remove duplicate functions

- Remove send_success_email/send_error_email from email_sender.py
- Centralize subject logic in tasks.py using _get_subject()
- Use EMAIL_SUBJECT_SUCCESS and EMAIL_SUBJECT_ERROR with clear defaults
- Ensure subject is always set and logged before sending

scraibe/tasks.py

@@ -164,22 +164,10 @@ def send_success_email(
     Subject is customizable via EMAIL_SUBJECT_SUCCESS.
     Falls back to a safe default if the env var is missing or blank.
     """
-    # Read subject from environment; never allow blank
-    raw_subject = os.getenv("EMAIL_SUBJECT_SUCCESS")
-    subject = (raw_subject or "").strip()
-
-    if not subject:
-        subject = "ScrAIbe: Your transcript is ready"
-        logger.info(
-            "EMAIL_SUBJECT_SUCCESS not set or blank; using default subject: %s", subject
-        )
-    else:
-        logger.info("Using EMAIL_SUBJECT_SUCCESS: %s", subject)
-
-    # Final guard: ensure subject is never empty
-    if not subject:
-        subject = "ScrAIbe: Your transcript is ready"
-        logger.warning("Subject was empty after reading; forced default subject.")
+    subject = _get_subject(
+        "EMAIL_SUBJECT_SUCCESS",
+        "ScrAIbe: Your transcript is ready",
+    )
 
     body = (
         "Hello,\n\n"