feat: Add option to toggle connector arrows

Implements a toggle switch in the connector controls menu that allows
users to show or hide arrows on individual connectors. Arrows are
shown by default for new connectors but can be toggled off for each
connector independently.

Closes #74

packages/fossflow-lib/src/components/ItemControls/ConnectorControls/ConnectorControls.tsx

@@ -6,7 +6,9 @@ import {
   Select,
   MenuItem,
   TextField,
-  IconButton as MUIIconButton
+  IconButton as MUIIconButton,
+  FormControlLabel,
+  Switch
 } from '@mui/material';
 import { useConnector } from 'src/hooks/useConnector';
 import { ColorSelector } from 'src/components/ColorSelector/ColorSelector';
@@ -97,6 +99,21 @@ export const ConnectorControls = ({ id }: Props) => {
             })}
           </Select>
         </Section>
+        <Section>
+          <FormControlLabel
+            control={
+              <Switch
+                checked={connector.showArrow !== false}
+                onChange={(e) => {
+                  updateConnector(connector.id, {
+                    showArrow: e.target.checked
+                  });
+                }}
+              />
+            }
+            label="Show Arrow"
+          />
+        </Section>
         <Section>
           <Box>
             <DeleteButton

packages/fossflow-lib/src/components/SceneLayers/Connectors/Connector.tsx

@@ -144,7 +144,7 @@ export const Connector = ({ connector: _connector, isSelected }: Props) => {
           );
         })}
 
-        {directionIcon && (
+        {directionIcon && connector.showArrow !== false && (
           <g transform={`translate(${directionIcon.x}, ${directionIcon.y})`}>
             <g transform={`rotate(${directionIcon.rotation})`}>
               <polygon

packages/fossflow-lib/src/config.ts

@@ -49,7 +49,8 @@ export const CONNECTOR_DEFAULTS: Required<Omit<Connector, 'id' | 'color'>> = {
   width: 10,
   description: '',
   anchors: [],
-  style: 'SOLID'
+  style: 'SOLID',
+  showArrow: true
 };
 
 // The boundaries of the search area for the pathfinder algorithm

packages/fossflow-lib/src/schemas/connector.ts

@@ -20,5 +20,6 @@ export const connectorSchema = z.object({
   color: id.optional(),
   width: z.number().optional(),
   style: z.enum(connectorStyleOptions).optional(),
+  showArrow: z.boolean().optional(),
   anchors: z.array(anchorSchema)
 });