Can I vibecode Sendible?

Build a robust, self-hosted social media management and scheduling workspace inspired by Sendible, tailored for agency-style workflows with client separation, without attempting to reverse-engineer closed platform APIs.
Use exactly this stack: Next.js 15 (App Router), TypeScript, PostgreSQL, Drizzle ORM, and BullMQ (for background job processing).

### Data Model & Schema
Design a structured PostgreSQL schema using Drizzle:
- `users`: id, email, name, role (admin, manager, client).
- `workspaces`: id, name, type (e.g., specific client or brand).
- `workspace_members`: workspaceId, userId, role.
- `social_profiles`: id, workspaceId, platform (Twitter, LinkedIn, Facebook, Instagram), accountName, status, token (encrypted).
- `posts`: id, workspaceId, content, mediaUrls (array), status (draft, pending_approval, scheduled, published, failed), scheduledAt, authorId, approvedById.
- `post_variants`: id, postId, platform, tailoredContent.
- `content_categories`: id, workspaceId, name, color (for calendar color-coding).

### Screens and UX Patterns
1. **Unified Agency Dashboard**: An overview screen showing upcoming scheduled posts across all active workspaces/clients, with a top-level workspace switcher.
2. **Interactive Content Calendar**: A full-month calendar view where users can drag-and-drop posts to reschedule them, color-coded by platform or category.
3. **Compose Box & Previewer**: A rich authoring interface to draft a post once, with a toggle to tailor the message for specific platforms (e.g., removing hashtags for LinkedIn, adding them for Instagram). Includes a side-by-side simulated preview of the native platform look.
4. **Approval Workflow**: A Kanban-style "Tasks" view for drafts awaiting client or manager approval before they can be scheduled.
5. **Asset Library**: A simple media manager for uploading and reusing images across different posts.

### Step-by-Step User Journeys
1. **Onboarding & Workspace Creation**: An agency admin creates a Workspace for "Client A", connects dummy social profiles (since we aren't bypassing real APIs), and invites a client user with 'approval-only' rights.
2. **Drafting**: A social media manager writes a post, uploads an image, tailors the Twitter variant to fit character limits, and sets it to 'pending_approval'.
3. **Approval**: The client logs in, reviews the post in their specific workspace, and clicks 'Approve'.
4. **Scheduling & "Publishing"**: The system moves the post to 'Scheduled'. A BullMQ worker picks it up at the scheduled time. Instead of hitting closed APIs, it marks it as "Ready for Manual Export" or triggers an optional configured webhook, keeping the tool useful as a planner.

### Technical Specifics
- Implement Role-Based Access Control (RBAC) meticulously to ensure strict data separation between workspaces (clients cannot see other clients' data).
- Rely on BullMQ and Redis for queueing and managing scheduled publishing jobs.
- Do not fake native integrations, proprietary reporting metrics, or direct publishing reliability against changing APIs.
- Put every secret and external credential in `.env` and provide `.env.example`.
- Add local export functionalities so users are not trapped in the app.
- Write focused unit tests for the RBAC model and the post state machine (draft -> approval -> scheduled).
- Provide a README with setup instructions, architecture of the multi-tenant workspaces, and instructions for running a production-style local build.