Complete Stackless parity: Activity, Deploy, Settings, header desc

- Add project description line to project header (from productVision)
- Sidebar: add Activity nav item (Projects / Activity / Settings)
- New Activity page: timeline feed with type filters (Atlas/Builds/Deploys/You)
- New Activity layout using VIBNSidebar
- Rewrite Deploy tab: Project URLs, Custom Domain, Env Vars, Deploy History
  — fully Stackless style, real data from project API, no more MOCK_PROJECT
- Rewrite Project Settings tab: remove all Firebase refs (db, auth, Firestore)
  — General (name/description), Repo link, Collaborators, Export JSON/PDF,
  — Danger Zone with double-confirm delete
  — uses /api/projects/[id] PATCH for saves

Made-with: Cursor

app/[workspace]/project/[projectId]/layout.tsx

@@ -3,6 +3,7 @@ import { query } from "@/lib/db-postgres";
 
 interface ProjectData {
   name: string;
+  description?: string;
   status?: string;
   progress?: number;
   discoveryPhase?: number;
@@ -22,6 +23,7 @@ async function getProjectData(projectId: string): Promise<ProjectData> {
       const { data, created_at, updated_at } = rows[0];
       return {
         name: data?.productName || data?.name || "Project",
+        description: data?.productVision || data?.description,
         status: data?.status,
         progress: data?.progress ?? 0,
         discoveryPhase: data?.discoveryPhase ?? 0,
@@ -52,6 +54,7 @@ export default async function ProjectLayout({
       workspace={workspace}
       projectId={projectId}
       projectName={project.name}
+      projectDescription={project.description}
       projectStatus={project.status}
       projectProgress={project.progress}
       discoveryPhase={project.discoveryPhase}