feat(phase-3): Complete AI content generation system

- Add /api/generate endpoints for AI content generation
- Integrate DeepSeek AI into dashboard compose page
- Add content templates for tips, products, services, engagement
- Implement batch generation for weekly/monthly calendars
- Add cost estimation endpoint

New endpoints:
- POST /api/generate/tip - Generate tech tips
- POST /api/generate/product - Generate product posts
- POST /api/generate/service - Generate service posts
- POST /api/generate/thread - Generate educational threads
- POST /api/generate/response - Generate response suggestions
- POST /api/generate/adapt - Adapt content to platform
- POST /api/generate/improve - Improve existing content
- POST /api/generate/batch - Batch generate for calendar
- GET /api/generate/batch/estimate - Estimate batch costs
- GET /api/generate/status - Check AI connection

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/main.py

@@ -11,7 +11,7 @@ from fastapi import FastAPI
 from fastapi.staticfiles import StaticFiles
 from fastapi.middleware.cors import CORSMiddleware
 
-from app.api.routes import posts, products, services, calendar, dashboard, interactions, auth, publish
+from app.api.routes import posts, products, services, calendar, dashboard, interactions, auth, publish, generate
 from app.core.config import settings
 from app.core.database import engine
 from app.models import Base
@@ -63,6 +63,7 @@ app.include_router(services.router, prefix="/api/services", tags=["Services"])
 app.include_router(calendar.router, prefix="/api/calendar", tags=["Calendar"])
 app.include_router(interactions.router, prefix="/api/interactions", tags=["Interactions"])
 app.include_router(publish.router, prefix="/api/publish", tags=["Publish"])
+app.include_router(generate.router, prefix="/api/generate", tags=["AI Generation"])
 
 
 @app.get("/api/health")