style: Replace Bug icons with Webhook icons

Replaced all Bug icons with Webhook icons throughout the app:
- Updated sidebar navigation icon for Spiders
- Updated spiders page table icon
- Updated empty state icon on spiders page

Better represents the spider/scraping functionality.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

app/(dashboard)/spiders/page.tsx

@@ -33,7 +33,7 @@ import {
   TableHeader,
   TableRow,
 } from "@/components/ui/table";
-import { Bug, PlayCircle, AlertCircle } from "lucide-react";
+import { Webhook, PlayCircle, AlertCircle } from "lucide-react";
 import { ListProjects, ListSpiders, ScheduleJob } from "@/lib/types";
 import { Textarea } from "@/components/ui/textarea";
 
@@ -172,7 +172,7 @@ export default function SpidersPage() {
                       <TableRow key={spider}>
                         <TableCell>
                           <div className="flex items-center gap-2 whitespace-nowrap">
-                            <Bug className="h-4 w-4 text-muted-foreground" />
+                            <Webhook className="h-4 w-4 text-muted-foreground" />
                             <span className="font-medium">{spider}</span>
                           </div>
                         </TableCell>
@@ -273,7 +273,7 @@ export default function SpidersPage() {
       {!selectedProject && !isProjectsLoading && (
         <Card>
           <CardContent className="flex flex-col items-center justify-center py-12">
-            <Bug className="mb-4 h-12 w-12 text-muted-foreground" />
+            <Webhook className="mb-4 h-12 w-12 text-muted-foreground" />
             <h3 className="mb-2 text-lg font-semibold">Select a project</h3>
             <p className="text-sm text-muted-foreground">
               Choose a project to view its spiders