add seating plan legend, improve ui

src/ez_lan_manager/components/SeatingPlanInfoBox.py

@@ -10,6 +10,7 @@ class SeatingPlanInfoBox(Component):
     seat_occupant: Optional[str] = None
     seat_price: int = 0
     is_blocked: bool = False
+    user_has_seat: bool = False
 
     def build(self) -> Component:
         if self.is_blocked:
@@ -22,5 +23,20 @@ class SeatingPlanInfoBox(Component):
             min_height=10
         ) if self.seat_id and self.seat_occupant else Column(
             Text(f"Dieser Sitzplatz ({self.seat_id}) ist frei", margin=1, style=TextStyle(fill=self.session.theme.neutral_color), wrap=True, justify="center"),
-            Button(Text(f"Buchen ({AccountingService.make_euro_string_from_int(self.seat_price)})", margin=1, style=TextStyle(fill=self.session.theme.neutral_color, font_size=1.1), wrap=True, justify="center"), shape="rounded", style="major", color="secondary", margin=1, grow_y=False), min_height=10
+            Button(
+                Text(
+                    f"Buchen ({AccountingService.make_euro_string_from_int(self.seat_price)})",
+                    margin=1,
+                    style=TextStyle(fill=self.session.theme.neutral_color, font_size=1.1),
+                    wrap=True,
+                    justify="center"
+                ),
+                shape="rounded",
+                style="major",
+                color="secondary",
+                margin=1,
+                grow_y=False,
+                is_sensitive=not self.user_has_seat
+            ),
+            min_height=10
         )