style: fix no-unused-vars -- prefix unused catch bindings, remove dead code, suppress template-use false positives

frontend/src/lib/components/admin/BookingCreateModal.svelte

@@ -146,8 +146,6 @@
 			!customServiceErrors.minimum_age_required
 	);
 
-	function toggleCustomForm(show: boolean) {
-		showCustomCreateForm = show;
 		if (show) {
 			newCustomService = {
 				name: '',
@@ -326,7 +324,6 @@
 			: !!(guestName.trim() && guestPhone.trim() && isValidUKPhone(guestPhone))
 	);
 	const canProceedStep2 = $derived(selectedServices.length > 0);
-	const canProceedStep3 = $derived(true); // Overrides are optional
 	const canProceedStep4 = $derived(!!(selectedDate && selectedTime));
 
 	/** Whether the currently selected time slot is out-of-hours */
@@ -487,7 +484,7 @@
 					(user: { account_role: string }) => !excludedRoles.includes(user.account_role)
 				);
 			}
-		} catch (err) {
+		} catch (_err) {
 			toast.error('Failed to load users');
 		} finally {
 			loadingUsers = false;
@@ -508,7 +505,7 @@
 			if (response.ok) {
 				services = await response.json();
 			}
-		} catch (err) {
+		} catch (_err) {
 			toast.error('Failed to load services');
 		} finally {
 			loadingServices = false;
@@ -582,7 +579,7 @@
 				workingHours = { ...workingHours, ...whMap };
 				availableHours = { ...availableHours, ...ahMap };
 			}
-		} catch (err) {
+		} catch (_err) {
 			toast.error('Failed to load availability');
 		} finally {
 			_loadingWorkingHours = false;
@@ -652,7 +649,7 @@
 				workingHours = { ...workingHours, ...whMap };
 				availableHours = { ...availableHours, ...ahMap };
 			}
-		} catch (err) {
+		} catch (_err) {
 			toast.error('Failed to load availability');
 		} finally {
 			_loadingWorkingHours = false;
@@ -742,7 +739,7 @@
 				toast.error(`Failed to reserve slot: ${errorText}`);
 				return false;
 			}
-		} catch (err) {
+		} catch (_err) {
 			toast.error('Failed to reserve slot');
 			return false;
 		} finally {
@@ -1042,7 +1039,7 @@
 				const errorText = await res.text();
 				toast.error(`Failed to create booking: ${errorText}`);
 			}
-		} catch (err) {
+		} catch (_err) {
 			toast.error('An error occurred while creating booking');
 		} finally {
 			submitting = false;