Rebrand Vaisu to VeilTalk

[Dr-Agentic]

This issue tracks the comprehensive rebranding of the application from Vaisu to VeilTalk.

Strategy

• Identity: Full rename of project metadata and visible branding.
• Infrastructure: Fresh start with new resource names (veiltalk-*).
• Assets: Rename existing V-logo assets to match new naming convention.

Tasks

1. Project Metadata & Configuration

• Root: Update package.json name to veiltalk.
• Backend: Update backend/package.json name to veiltalk-backend.
• Frontend: Update frontend/package.json name to veiltalk-frontend.
• Render: Update render.yaml service name and default environment variables.

2. Infrastructure Defaults (Backend)

• AWS Config: Update backend/src/config/aws.ts default table/bucket names (replace vaisu- prefix with veiltalk-).
• Setup Script: Update backend/scripts/setup-dynamodb.ts to create veiltalk-* tables.
• NPM Scripts: Update setup:s3 in backend/package.json to create s3://veiltalk-documents-dev.

3. Frontend & Visual Assets

• Asset Renaming:
  • Rename frontend/public/vaisu-favicon.png → veiltalk-favicon.png
  • Rename frontend/public/vaisu-splash.png → veiltalk-splash.png
• HTML Entry: Update frontend/index.html:
  • Title: "VeilTalk - Text to Visual Intelligence"
  • Icon/Image references.
• UI Text: Find and replace "Vaisu" with "VeilTalk" in React components (Sidebar, Splash, etc.).
• Theme: Update theme storage key to veiltalk-theme.

4. Documentation

• Update root README.md.
• Update backend/README.md.
• Update frontend/README.md.
• Update AGENTS.md.