Implement newsletter scheduling features

- Added a background scheduler to manage newsletter dispatch based on user-defined settings.
- Enhanced the SMTP settings to include scheduling options such as frequency, time, and specific weekdays.
- Updated the dashboard UI to allow users to configure scheduling preferences for automated newsletter sending.
- Modified the newsletter generation logic to accommodate new scheduling parameters and ensure proper content delivery.

app/services/newsletter.py

@@ -101,12 +101,9 @@ def split_articles_by_type(articles: list[dict[str, Any]]) -> tuple[list[dict[st
     return new_articles, edited_articles
 
 
-def create_subject(days: int, category: str = "", period_label: str | None = None) -> str:
-    label = period_label or f"{days} Tage"
-    base = f"Interner Wiki-Newsletter – {ORG_NAME} ({label})"
-    if category.strip():
-        return f"{base} | Kategorie: {category.strip()}"
-    return base
+def create_subject(month_label: str | None = None, days: int = 30) -> str:
+    label = month_label or f"{days} Tage"
+    return f"Neue Wiki-Artikel Veröffentlichungen vom {label} | Wiki-Redaktion"
 
 
 _MONTHS_DE = [
@@ -138,6 +135,7 @@ def resolve_period(mode: str, days: int) -> dict[str, Any]:
             "start_str": start.strftime("%d.%m.%Y"),
             "end_str": end.strftime("%d.%m.%Y"),
             "label": _month_label(start),
+            "month_label": _month_label(start),
             "days": max(1, (end - start).days),
         }
     days = max(1, min(days, 90))
@@ -150,6 +148,7 @@ def resolve_period(mode: str, days: int) -> dict[str, Any]:
         "start_str": start.strftime("%d.%m.%Y"),
         "end_str": end.strftime("%d.%m.%Y"),
         "label": f"{days} Tage",
+        "month_label": _month_label(end),
         "days": days,
     }
 
@@ -296,6 +295,7 @@ def create_html(
     period_label: str | None = None,
     period: tuple[str, str] | None = None,
     article_type: str = "all",
+    month_label: str | None = None,
 ) -> str:
     display = display or DEFAULT_DISPLAY
     new_articles, edited_articles = split_articles_by_type(articles)
@@ -303,7 +303,7 @@ def create_html(
     show_edited = article_type in ("all", "edited")
     period_start, period_end = period if period else _period_range(days)
     total = len(new_articles) + len(edited_articles)
-    subject = escape(create_subject(days, category, period_label))
+    subject = escape(create_subject(month_label or period_label, days))
     preheader = escape(_summary_sentence(total))
     period_label = escape(f"{period_start} – {period_end}")
     summary_text = escape(_summary_sentence(total))
@@ -678,6 +678,7 @@ def create_outlook_html(
     period_label: str | None = None,
     period: tuple[str, str] | None = None,
     article_type: str = "all",
+    month_label: str | None = None,
 ) -> str:
     """Word/Outlook-kompatibles HTML mit font-Tags und bgcolor (überlebt Einfügen in Outlook)."""
     display = display or DEFAULT_DISPLAY
@@ -686,7 +687,7 @@ def create_outlook_html(
     show_edited = article_type in ("all", "edited")
     period_start, period_end = period if period else _period_range(days)
     total = len(new_articles) + len(edited_articles)
-    subject = escape(create_subject(days, category, period_label))
+    subject = escape(create_subject(month_label or period_label, days))
     period_label = f"{period_start} – {period_end}"
     summary_text = _summary_sentence(total)