feat(migrate): wire GitHub PAT through to agent runner mirror call

MigrateSetup now sends the PAT field to the API; create route
forwards it as github_token so the agent runner can clone private repos.

Made-with: Cursor

components/project-creation/MigrateSetup.tsx

@@ -46,9 +46,8 @@ export function MigrateSetup({ workspace, onClose, onBack }: SetupProps) {
           slug: name.toLowerCase().replace(/[^a-z0-9]+/g, "-"),
           product: { name: name.trim() },
           creationMode: "migration",
-          // Top-level fields the create route reads for the mirror flow
           githubRepoUrl: repoUrl.trim() || undefined,
-          // Preserve extra metadata for future use
+          githubToken: pat.trim() || undefined,
           sourceData: {
             liveUrl: liveUrl.trim() || undefined,
             hosting: hosting || undefined,