feat(api): implement FastAPI routes with JWT authentication

- jokes.py: Public joke listing, detail, and random endpoints
- categories.py: Type and crowd listing endpoints
- auth.py: Login endpoint with JWT token generation
- admin.py: Full CRUD for jokes, types, crowds with JWT protection
- Fix request body schemas to use Create DTOs instead of Response models

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

api/main.py

@@ -2,6 +2,7 @@ from fastapi import FastAPI
 from fastapi.middleware.cors import CORSMiddleware
 
 from app.config import API_TITLE, API_VERSION
+from app.routers import jokes_router, categories_router, auth_router, admin_router
 
 # Create FastAPI application
 app = FastAPI(title=API_TITLE, version=API_VERSION)
@@ -15,6 +16,12 @@ app.add_middleware(
     allow_headers=["*"],
 )
 
+# Mount routers
+app.include_router(jokes_router)
+app.include_router(categories_router)
+app.include_router(auth_router)
+app.include_router(admin_router)
+
 
 @app.get("/")
 def root():