docs: fix Next.js 14→15 references, add libs READMEs

- Fix remaining "Next.js 14" references in:
  - docs/architecture/IMPLEMENTATION_QUICK_REFERENCE.md
  - docs/load-testing/K6_LOAD_TESTING_GUIDE.md
- Create README.md for libs/ai-services/ (FastAPI AVM, moderation, NLP)
- Create README.md for libs/mcp-servers/ (MCP tool server library)
- Note: CLAUDE.md, README.md, and docs/architecture.md were already
  updated in a prior pass

Co-Authored-By: Paperclip <noreply@paperclip.ing>

docs/architecture/IMPLEMENTATION_QUICK_REFERENCE.md

@@ -3,7 +3,7 @@
 ## 🎯 Key Findings at a Glance
 
 ### Current State
-- ✅ **Next.js 14** with App Router (well-structured)
+- ✅ **Next.js 15** with App Router (well-structured)
 - ✅ **React 18** + TypeScript (type-safe)
 - ✅ **Tailwind CSS** with dark mode support (HSL-based theme)
 - ✅ **Good component library** (~35 components)

docs/load-testing/K6_LOAD_TESTING_GUIDE.md

@@ -15,7 +15,7 @@
 ```
 goodgo-platform/
 ├── apps/api                 # NestJS backend (port 3001)
-├── apps/web                 # Next.js 14 frontend (port 3000)
+├── apps/web                 # Next.js 15 frontend (port 3000)
 ├── libs/mcp-servers         # MCP tool server library
 ├── prisma/                  # Database schema & migrations
 ├── e2e/                     # Playwright E2E tests (api + web)

libs/ai-services/README.md

@@ -0,0 +1,69 @@
+# @goodgo/ai-services
+
+Python FastAPI AI/ML microservice for the GoodGo Platform.
+
+## Services
+
+| Service | Router | Description |
+|---------|--------|-------------|
+| **AVM** | `/avm` | Automated Valuation Model — XGBoost-based property price predictions |
+| **Moderation** | `/moderation` | Content moderation for listings (text + image analysis) |
+| **NLP** | `/nlp` | Vietnamese NLP — feature extraction, search query understanding |
+
+## Tech Stack
+
+- **Python** 3.12+
+- **FastAPI** 0.115 + Uvicorn
+- **XGBoost** 2.1 (property valuation model)
+- **Underthesea** 6.8 (Vietnamese NLP tokenizer)
+- **Pydantic** 2.9 (request/response schemas)
+
+## Quick Start
+
+```bash
+# Via Docker (recommended — runs as part of the platform stack)
+docker compose up -d ai-services
+
+# Standalone
+cd libs/ai-services
+pip install -e ".[dev]"
+uvicorn app.main:app --reload --port 8000
+```
+
+## Project Structure
+
+```
+libs/ai-services/
+├── app/
+│   ├── main.py          # FastAPI app entry point
+│   ├── config.py        # Settings (Pydantic BaseSettings)
+│   ├── middleware.py     # CORS, rate limiting, error handling
+│   ├── models/          # Pydantic request/response schemas
+│   │   ├── avm.py
+│   │   ├── moderation.py
+│   │   └── nlp.py
+│   ├── routers/         # API route handlers
+│   │   ├── avm.py
+│   │   ├── moderation.py
+│   │   └── nlp.py
+│   └── services/        # Business logic
+│       ├── avm_service.py
+│       ├── moderation_service.py
+│       └── nlp_service.py
+├── tests/               # pytest test suite
+├── Dockerfile           # Production container image
+└── pyproject.toml       # Dependencies and config
+```
+
+## Testing
+
+```bash
+cd libs/ai-services
+pytest
+```
+
+## Health Check
+
+```
+GET /health → {"status": "ok"}
+```

libs/mcp-servers/README.md

@@ -0,0 +1,54 @@
+# @goodgo/mcp-servers
+
+MCP (Model Context Protocol) tool server library for the GoodGo Platform. Provides structured tools that AI assistants can use to query property data, run analytics, and perform valuations.
+
+## Tool Servers
+
+| Server | Path | Description |
+|--------|------|-------------|
+| **Property Search** | `property-search/` | Geo search, full-text search, filter by type/price/area |
+| **Market Analytics** | `market-analytics/` | Price trends, heatmaps, district comparisons |
+| **Valuation** | `valuation/` | AVM property valuation requests |
+
+## Tech Stack
+
+- **TypeScript** 6+
+- **@modelcontextprotocol/sdk** 1.12 (MCP protocol implementation)
+- **Zod** 3.24 (schema validation)
+- **NestJS** integration module (optional peer dependency)
+
+## Project Structure
+
+```
+libs/mcp-servers/
+├── src/
+│   ├── index.ts            # Public API exports
+│   ├── property-search/    # Property search tool server
+│   ├── market-analytics/   # Market analytics tool server
+│   ├── valuation/          # AVM valuation tool server
+│   ├── nestjs/             # NestJS module integration
+│   ├── shared/             # Shared types and utilities
+│   └── __tests__/          # Test suite
+├── package.json
+└── tsconfig.json
+```
+
+## Usage
+
+```typescript
+import { PropertySearchServer, MarketAnalyticsServer } from '@goodgo/mcp-servers';
+```
+
+The MCP endpoints are exposed via the API's `apps/api/src/modules/mcp/` module.
+
+## Building
+
+```bash
+pnpm --filter @goodgo/mcp-servers build
+```
+
+## Testing
+
+```bash
+pnpm --filter @goodgo/mcp-servers test
+```