Add Launch, Grow, Insights tabs; rename Deploy → Launch

- Rename Deploy tab label to Launch in ProjectShell
- Add Grow and Insights placeholder pages with Stackless styling

Made-with: Cursor

components/layout/project-shell.tsx

@@ -26,7 +26,9 @@ const TABS = [
   { id: "prd",         label: "PRD",      path: "prd" },
   { id: "design",      label: "Design",   path: "design" },
   { id: "build",       label: "Build",    path: "build" },
-  { id: "deployment",  label: "Deploy",   path: "deployment" },
+  { id: "deployment",  label: "Launch",   path: "deployment" },
+  { id: "grow",        label: "Grow",     path: "grow" },
+  { id: "insights",    label: "Insights", path: "insights" },
   { id: "settings",    label: "Settings", path: "settings" },
 ];