feat(ui): add GitHub integration UI components

Add complete frontend implementation for GitHub integration following
the same pattern as Jira integration.

Components:
- GitHubIntegrationForm: Form for creating/editing GitHub integrations
- GitHubIntegrationsManager: Manager component for listing and managing integrations
- GitHubIntegrationCard: Card component for main integrations page
- GitHub integration page at /integrations/github

Features:
- Personal Access Token input with validation
- Optional repository owner filter
- Connection testing and repository discovery
- Enable/disable integration toggle
- Edit credentials functionality
- Delete integration with confirmation
- Pagination support
- Integration status display with last checked timestamp

Server Actions:
- getGitHubIntegrations(): Fetch enabled GitHub integrations
- sendFindingToGitHub(): Send finding to GitHub as issue
- pollGitHubDispatchTask(): Poll async task completion

Types & Schemas:
- githubIntegrationFormSchema: Zod schema for creation
- editGitHubIntegrationFormSchema: Zod schema for editing
- GitHubCredentialsPayload: TypeScript interface for credentials
- GitHubDispatchRequest/Response: API types for dispatching

Integration Page:
- Created /integrations/github page with features list
- Added GitHub card to main integrations overview
- Exported GitHub components from integrations index

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

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

ui/components/integrations/github/github-integration-card.tsx

@@ -0,0 +1,54 @@
+"use client";
+
+import { GithubIcon, SettingsIcon } from "lucide-react";
+import Link from "next/link";
+
+import { Button } from "@/components/shadcn";
+import { CustomLink } from "@/components/ui/custom/custom-link";
+
+import { Card, CardContent, CardHeader } from "../../shadcn";
+
+export const GitHubIntegrationCard = () => {
+  return (
+    <Card variant="base" padding="lg">
+      <CardHeader>
+        <div className="flex w-full flex-col items-start gap-2 sm:flex-row sm:items-center sm:justify-between">
+          <div className="flex items-center gap-3">
+            <GithubIcon size={40} className="text-gray-900 dark:text-gray-100" />
+            <div className="flex flex-col gap-1">
+              <h4 className="text-lg font-bold text-gray-900 dark:text-gray-100">
+                GitHub
+              </h4>
+              <div className="flex flex-col items-start gap-2 sm:flex-row sm:items-center">
+                <p className="text-xs text-nowrap text-gray-500 dark:text-gray-300">
+                  Create security issues in GitHub repositories.
+                </p>
+                <CustomLink
+                  href="https://docs.prowler.com"
+                  aria-label="Learn more about GitHub integration"
+                  size="xs"
+                >
+                  Learn more
+                </CustomLink>
+              </div>
+            </div>
+          </div>
+          <div className="flex items-center gap-2 self-end sm:self-center">
+            <Button asChild size="sm">
+              <Link href="/integrations/github">
+                <SettingsIcon size={14} />
+                Manage
+              </Link>
+            </Button>
+          </div>
+        </div>
+      </CardHeader>
+      <CardContent>
+        <p className="text-sm text-gray-600 dark:text-gray-300">
+          Configure and manage your GitHub integrations to automatically create
+          issues for security findings in your GitHub repositories.
+        </p>
+      </CardContent>
+    </Card>
+  );
+};