rename: replace all user-facing 'Atlas' references with 'Vibn'

Updated UI text in: project-shell (tab label), AtlasChat (sender name),
FreshIdeaMain, TypeSelector, MigrateSetup, ChatImportSetup, FreshIdeaSetup,
CodeImportSetup, prd/page, build/page, projects/page, deployment/page,
activity/page, layout (page title/description), atlas-chat API route.
Code identifiers (AtlasChat component name, file names) unchanged.

Made-with: Cursor

app/[workspace]/projects/page.tsx

@@ -299,7 +299,7 @@ export default function ProjectsPage() {
             No projects yet
           </h3>
           <p style={{ fontSize: "0.82rem", color: "#a09a90", lineHeight: 1.6, marginBottom: 24 }}>
-            Tell Atlas what you want to build and it will figure out the rest.
+            Tell Vibn what you want to build and it will figure out the rest.
           </p>
           <button
             onClick={() => setShowNew(true)}