📚 Add AGENTS.md - Project knowledge base

Comprehensive documentation for AI agents:
✅ Project structure and conventions
✅ Deployment instructions (Dockerfile + Easypanel)
✅ Page structure and routing
✅ Data structure (site-config.ts)
✅ Styling guidelines (Tailwind + custom classes)
✅ Image handling and SEO
✅ Anti-patterns and best practices
✅ Commands and environment setup

Based on commit 668f690 (ideal Next.js setup)

AGENTS.md

@@ -1,8 +1,8 @@
 # DEAL PLUS TECH - PROJECT KNOWLEDGE BASE
 
-**Generated:** 2026-03-01
+**Generated:** 2026-03-10  
-**Commit:** 13436b4
+**Commit:** 668f690  
-**Branch:** main
+**Branch:** main  
 
 ## OVERVIEW
 
@@ -26,11 +26,11 @@ src/
 | Task | Location | Notes |
 |------|----------|-------|
 | Add/edit pages | `src/app/*/page.tsx` | App Router conventions |
-| Add products | `src/data/site-config.ts` | ProductCategory array |
+| Add/edit products | `src/data/site-config.ts` | ProductCategory array |
 | Add product tables | `src/data/product-tables.ts` | Table data for specs |
 | UI components | `src/components/ui/` | Button, Card, Badge |
 | Layout | `src/components/layout/` | Header, Footer, FloatingContact |
-| Types | `src/types/index.ts` | All interfaces |
+| Types | `src/types/index.ts` | All TypeScript interfaces |
 | Styling | `src/styles/globals.css` | Custom component classes |
 | SEO/Metadata | `src/app/layout.tsx` | Root metadata + schema |
 
@@ -56,12 +56,38 @@ src/
 
 **Path alias**: `@/*` maps to `./src/*`
 
+## DEPLOYMENT
+
+### Dockerfile (Production)
+
+```dockerfile
+# Multi-stage build for Next.js
+FROM node:20-alpine AS deps
+# ... (see Dockerfile for full config)
+```
+
+**Easypanel Configuration:**
+- **Build Type:** Dockerfile
+- **Dockerfile Path:** `./Dockerfile`
+- **Port:** 3000
+
+**To Deploy:**
+1. Push to Git main branch
+2. Easypanel auto-detects and rebuilds
+3. Wait 2-3 minutes for build
+4. Site is live
+
+### Alternative: Nixpacks
+
+If Dockerfile build fails, Easypanel can auto-detect and use Nixpacks.
+
 ## ANTI-PATTERNS (THIS PROJECT)
 
 - **DO NOT** use `output: 'standalone'` in dev mode (breaks HMR)
 - **DO NOT** hardcode contact info - use `siteConfig` from `@/data/site-config`
 - **DO NOT** add tests - project has no test infrastructure
-- **DO NOT** use `as any` or `@ts-ignore` - strict mode enabled
+- **DO NOT** use `as any`, `@ts-ignore`, `@ts-expect-error` - strict mode enabled
+- **DO NOT** modify CSS unless necessary - preserve existing design
 
 ## UNIQUE STYLES
 
@@ -88,8 +114,90 @@ npm run lint     # ESLint check
 
 ## NOTES
 
-- No CI/CD configured - manual deployments
+- No CI/CD configured - manual deployments via Easypanel
 - Environment variables in `.env.local` (copy from `.env.example`)
 - Large data files in `src/data/` - edit with care
 - Thai URLs require URL-encoded characters in some contexts
-- `public/llm.txt` contains AI-readable content for the site
+- `public/llm.txt` contains AI-readable content for the site
+
+## PAGES STRUCTURE
+
+| Route | File | Description |
+|-------|------|-------------|
+| `/` | `app/page.tsx` | Homepage with hero, featured products |
+| `/about-us/` | `app/about-us/page.tsx` | About company |
+| `/services/` | `app/services/page.tsx` | Services offered |
+| `/products/` | `app/product/page.tsx` | Product listing |
+| `/contact-us/` | `app/contact-us/page.tsx` | Contact form & info |
+| `/join-us/` | `app/join-us/page.tsx` | Careers/jobs |
+| `/sales-engineer/` | `app/sales-engineer/page.tsx` | Sales engineer info |
+| `/portfolio/` | `app/portfolio/page.tsx` | Project portfolio |
+| `/all-projects/` | `app/all-projects/page.tsx` | FAQ page |
+| `/blog/` | `app/blog/page.tsx` | Blog listing |
+| `/[slug]/` | `app/[slug]/page.tsx` | Dynamic product pages |
+
+## DATA STRUCTURE
+
+### site-config.ts
+
+```typescript
+interface ProductCategory {
+  id: string;
+  name: string;  // Thai
+  nameEn: string;  // English
+  slug: string;  // Thai URL slug
+  href: string;  // Full URL
+  description: string;
+  shortDescription: string;
+  image: string;
+  specifications: Array<{label: string; value: string; unit?: string}>;
+  features: string[];
+  applications: string[];
+  faq: Array<{question: string; answer: string}>;
+  schemaData: {...};
+}
+```
+
+### Key Config Sections:
+- `siteConfig` - Company info, contact details
+- `mainNavigation` - Header navigation items
+- `productCategories` - All products (20+ items)
+- `workHours` - Business hours
+- `socialLinks` - Social media links
+
+## IMAGE HANDLING
+
+**Location**: `public/images/`
+
+**Optimization**:
+- Next.js Image component auto-converts to AVIF/WebP
+- Remote patterns configured for external images
+- Sharp required for production builds
+
+**Best Practices**:
+- Use `next/image` component
+- Always provide `alt` text in Thai
+- Specify `width` and `height` to prevent layout shift
+
+## SEO
+
+**Metadata**:
+- Thai language meta tags
+- Open Graph tags for social sharing
+- Twitter Card support
+- Structured data (JSON-LD) for LocalBusiness
+
+**Thai URLs**:
+- All URLs in Thai language
+- URL-encoded where necessary
+- Trailing slashes preserved
+
+## BACKUP
+
+Old Next.js project backed up at:
+`/Users/kunthawatgreethong/Gitea/dealplustech-backup-nextjs-{DATE}.tar.gz`
+
+---
+
+**Last Updated:** 2026-03-10  
+**Status:** Production Ready