feat: Expand fleet to 23 skills across all domains

New skills (14):
- nestjs-best-practices: 40 priority-ranked rules (kadajett)
- fastapi: Pydantic v2, async SQLAlchemy, JWT auth (jezweb)
- architecture-patterns: Clean Architecture, Hexagonal, DDD (wshobson)
- python-performance-optimization: Profiling and optimization (wshobson)
- ai-sdk: Vercel AI SDK streaming and agent patterns (vercel)
- create-agent: Modular agent architecture with OpenRouter (openrouterteam)
- proactive-agent: WAL Protocol, compaction recovery, self-improvement (halthelobster)
- brand-guidelines: Brand identity enforcement (anthropics)
- ui-animation: Motion design with accessibility (mblode)
- marketing-ideas: 139 ideas across 14 categories (coreyhaines31)
- pricing-strategy: SaaS pricing and tier design (coreyhaines31)
- programmatic-seo: SEO at scale with playbooks (coreyhaines31)
- competitor-alternatives: Comparison page architecture (coreyhaines31)
- referral-program: Referral and affiliate programs (coreyhaines31)

README reorganized by domain: Code Quality, Frontend, Backend,
Auth, AI/Agent Building, Marketing, Design, Meta.

Mosaic Stack is not limited to coding — the Orchestrator serves
coding, business, design, marketing, writing, logistics, and analysis.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

skills/fastapi/templates/src/auth/service.py

@@ -0,0 +1,42 @@
+"""Authentication service - password hashing and JWT tokens."""
+
+from datetime import datetime, timedelta
+
+from jose import JWTError, jwt
+from passlib.context import CryptContext
+
+from src.config import settings
+
+# Password hashing
+pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")
+
+
+def hash_password(password: str) -> str:
+    """Hash a password using bcrypt."""
+    return pwd_context.hash(password)
+
+
+def verify_password(plain_password: str, hashed_password: str) -> bool:
+    """Verify a password against its hash."""
+    return pwd_context.verify(plain_password, hashed_password)
+
+
+def create_access_token(data: dict, expires_delta: timedelta | None = None) -> str:
+    """Create a JWT access token."""
+    to_encode = data.copy()
+    expire = datetime.utcnow() + (
+        expires_delta or timedelta(minutes=settings.ACCESS_TOKEN_EXPIRE_MINUTES)
+    )
+    to_encode.update({"exp": expire})
+    return jwt.encode(to_encode, settings.SECRET_KEY, algorithm=settings.ALGORITHM)
+
+
+def decode_token(token: str) -> dict | None:
+    """Decode and verify a JWT token. Returns None if invalid."""
+    try:
+        payload = jwt.decode(
+            token, settings.SECRET_KEY, algorithms=[settings.ALGORITHM]
+        )
+        return payload
+    except JWTError:
+        return None