feat: Fix hydration errors, navbar overlap, and add AI image generation system

## 🎨 UI/UX Fixes

### Fixed React Hydration Errors
- ActivityFeed: Standardized button styling (gradient → solid)
- ActivityFeed: Unified icon sizes and spacing for SSR/CSR consistency
- ActivityFeed: Added timestamps to chat messages for stable React keys
- About: Fixed duplicate keys in tech stack items (added unique key combinations)
- Projects: Fixed duplicate keys in project tags (combined projectId + tag + index)

### Fixed Layout Issues
- Added spacer after Header component (h-24 md:h-32) to prevent navbar overlap
- Hero section now properly visible below fixed navbar

## 🔧 Backend Improvements

### Database Schema
- Added ActivityStatus model for real-time activity tracking
- Supports: coding activity, music playing, watching, gaming, status/mood
- Single-row design (id=1) with auto-updating timestamps

### API Enhancements
- Fixed n8n status endpoint to handle missing table gracefully
- Added TypeScript interfaces (removed ESLint `any` warnings)
- New API: POST /api/n8n/generate-image for AI image generation
- New API: GET /api/n8n/generate-image?projectId=X for status check

## 🔐 Security & Auth

### Middleware Updates
- Removed premature auth redirect for /manage and /editor routes
- Pages now handle their own authentication (show login forms)
- Security headers still applied to all routes

## 🤖 New Feature: AI Image Generation System

### Complete automated project cover image generation using local Stable Diffusion

**Core Components:**
- Admin UI component (AIImageGenerator.tsx) with preview, generate, and regenerate
- n8n workflow integration for automation
- Context-aware prompt generation based on project metadata
- Support for 10+ project categories with optimized prompts

**Documentation (6 new files):**
- README.md - System overview and features
- SETUP.md - Detailed installation guide (486 lines)
- QUICKSTART.md - 15-minute quick start
- PROMPT_TEMPLATES.md - Category-specific templates (612 lines)
- ENVIRONMENT.md - Environment variables reference
- n8n-workflow-ai-image-generator.json - Ready-to-import workflow

**Database Migration:**
- SQL script: create_activity_status.sql
- Auto-setup script: quick-fix.sh
- Migration guide: prisma/migrations/README.md

**Key Features:**
✅ Automatic generation on project creation
✅ Manual regeneration via admin UI
✅ Category-specific prompts (web, mobile, devops, ai, game, etc.)
✅ Local Stable Diffusion (no API costs, privacy-first)
✅ n8n workflow orchestration
✅ Optimized for web (1024x768)

## 📝 Documentation

- CHANGELOG_DEV.md - Complete changelog with migration guide
- PRE_PUSH_CHECKLIST.md - Pre-push verification checklist
- Comprehensive AI image generation docs

## 🐛 Bug Fixes

1. Fixed "Hydration failed" errors in ActivityFeed
2. Fixed "two children with same key" warnings
3. Fixed navbar overlapping hero section
4. Fixed "relation activity_status does not exist" errors
5. Fixed /manage redirect loop (was going to home page)
6. Fixed TypeScript ESLint errors and warnings
7. Fixed duplicate transition prop in Hero component

## ⚠️ Breaking Changes

None - All changes are backward compatible

## 🔄 Migration Required

Database migration needed for new ActivityStatus table:
```bash
./prisma/migrations/quick-fix.sh
# OR
psql -d portfolio -f prisma/migrations/create_activity_status.sql
```

## 📦 Files Changed

**Modified (7):**
- app/page.tsx
- app/components/About.tsx
- app/components/Projects.tsx
- app/components/ActivityFeed.tsx
- app/components/Hero.tsx
- app/api/n8n/status/route.ts
- middleware.ts
- prisma/schema.prisma

**Created (14):**
- app/api/n8n/generate-image/route.ts
- app/components/admin/AIImageGenerator.tsx
- docs/ai-image-generation/* (6 files)
- prisma/migrations/* (3 files)
- CHANGELOG_DEV.md
- PRE_PUSH_CHECKLIST.md
- COMMIT_MESSAGE.txt

## ✅ Testing

- [x] Build successful: npm run build
- [x] Linting passed: npm run lint (0 errors, 8 warnings)
- [x] No hydration errors in console
- [x] No duplicate key warnings
- [x] /manage accessible (shows login form)
- [x] API endpoints responding correctly
- [x] Navbar no longer overlaps content

## 🚀 Next Steps

1. Test AI image generation with Stable Diffusion setup
2. Test n8n workflow integration
3. Create demo screenshots for new features
4. Update main README.md after merge

---
Co-authored-by: AI Assistant (Claude Sonnet 4.5)

app/components/Hero.tsx

@@ -204,7 +204,6 @@ const Hero = () => {
                 ease: [0.25, 0.1, 0.25, 1],
               }}
               whileHover={{ scale: 1.03, y: -3 }}
-              transition={{ duration: 0.3, ease: "easeOut" }}
               className="flex items-center space-x-2 px-5 py-2.5 rounded-full bg-white/70 border border-white/90 shadow-sm backdrop-blur-sm"
             >
               <feature.icon className="w-4 h-4 text-stone-700" />

app/components/admin/AIImageGenerator.tsx

@@ -10,6 +10,7 @@ import {
   CheckCircle,
   XCircle,
 } from "lucide-react";
+import Image from "next/image";
 
 interface AIImageGeneratorProps {
   projectId: number;
@@ -101,10 +102,11 @@ export default function AIImageGenerator({
           >
             <div className="aspect-[4/3] rounded-xl overflow-hidden border-2 border-stone-200 bg-stone-50">
               {generatedImageUrl ? (
-                <img
+                <Image
                   src={generatedImageUrl}
                   alt={projectTitle}
-                  className="w-full h-full object-cover"
+                  fill
+                  className="object-cover"
                 />
               ) : (
                 <div className="w-full h-full flex items-center justify-center">
@@ -153,7 +155,7 @@ export default function AIImageGenerator({
           whileHover={{ scale: 1.02 }}
           whileTap={{ scale: 0.98 }}
           onClick={() => handleGenerate(false)}
-          disabled={isGenerating || (!regenerate && !!generatedImageUrl)}
+          disabled={isGenerating || !!generatedImageUrl}
           className={`flex-1 py-3 px-4 rounded-xl font-semibold text-white transition-all duration-300 flex items-center justify-center gap-2 ${
             isGenerating
               ? "bg-stone-400 cursor-not-allowed"