feat: migrate website-creator from Next.js+Payload to Astro+Tina CMS

Major changes:
- Replace Payload CMS with Tina CMS (self-hosted)
- Add Astro DB for consent logging (PDPA compliant)
- Update Tailwind v3 to v4 (@tailwindcss/vite plugin)
- Add astro-tina-starter template
- Rewrite consent template for Astro (ConsentBanner.astro, Astro DB, Nano Stores)
- Add install-tina-backend.sh for self-hosted Tina per customer
- Rename convert-astro.sh to migrate-tina.sh
- Add AGENTS.md template for generated websites
- Delete all Payload/Next.js files

Technical updates:
- Astro DB using defineDb with eq operators for queries
- Tailwind v4 with @theme block
- Tina CMS local development mode
- Proper Astro API routes for consent

Research-verified with official documentation (April 2026)

skills/website-creator/templates/astro-tina-starter/README.md

@@ -0,0 +1,104 @@
+# Astro Tina Starter
+
+Astro 6.1.7 + Tina CMS starter template with Tailwind CSS 4.x
+
+## Tech Stack
+
+- **Framework:** Astro 6.1.7
+- **CMS:** Tina CMS (self-hosted)
+- **Styling:** Tailwind CSS 4.x with `@tailwindcss/vite`
+- **Database:** Astro DB (LibSQL)
+- **State:** Nano Stores + React
+- **Language:** TypeScript
+
+## Features
+
+- Self-hosted Tina CMS with schema-based content
+- Tailwind CSS 4.x using `@tailwindcss/vite` plugin
+- Astro DB for consent logging (PDPA compliant)
+- Nano Stores for client-side state management
+- Thai language support foundation
+- Docker-ready deployment
+
+## Quick Start
+
+```bash
+# Install dependencies
+npm install
+
+# Start development
+npm run dev
+
+# Build for production
+npm run build
+```
+
+## Tina CMS Access
+
+During development, access Tina CMS at:
+- http://localhost:4321/admin
+
+For production, you'll need a TINA_TOKEN environment variable.
+
+## Project Structure
+
+```
+astro-tina-starter/
+├── .tina/
+│   ├── config.ts      # Tina CMS configuration
+│   └── schema.ts       # Content schema definitions
+├── db/
+│   ├── config.ts       # Astro DB schema (consent logs)
+│   └── seed.ts         # Database seed script
+├── src/
+│   ├── styles/
+│   │   └── global.css  # Tailwind v4 styles
+│   ├── layouts/
+│   │   └── Layout.astro
+│   ├── pages/
+│   │   └── index.astro
+│   ├── components/
+│   │   └── Header.astro
+│   └── content/
+│       └── config.ts   # Tina content collections
+├── Dockerfile
+└── package.json
+```
+
+## Tailwind CSS 4.x
+
+This template uses Tailwind CSS 4.x with the `@tailwindcss/vite` plugin.
+The configuration is done via CSS `@theme` block in `src/styles/global.css`.
+
+```css
+@import "tailwindcss";
+
+@theme {
+  --color-primary: #1a1a1a;
+  --color-accent: #3b82f6;
+}
+```
+
+## Astro DB
+
+The template includes a consent-log table for PDPA compliance:
+
+```ts
+// db/config.ts
+export const ConsentLog = defineTable({
+  columns: {
+    action: text(),
+    purpose: text(),
+    analytics: boolean(),
+    marketing: boolean(),
+    functional: boolean(),
+    userAgent: text(),
+    ip: text(),
+    timestamp: text(),
+  },
+})
+```
+
+## License
+
+MIT