Stream D: Security hardening — 10 fixes from QA review

- SEC-05: Fail fast if SECRET_KEY is default 'change-me-in-production'
- SEC-06: CORS allow_credentials=False (Bearer tokens don't need it)
- SEC-08: Input validation on auth schemas (min/max length, username pattern)
- SEC-10: .dockerignore files (root, backend, mcp-connector)
- SEC-11: Hardcode ALGORITHM='HS256' as constant, remove from settings
- CQ-01: Gate crawl scheduler on CRAWL_ENABLED env var (default false)
- OS-02: CONTRIBUTING.md
- OS-03: CHANGELOG.md with v1.0.0 entry
- setup.ps1: Add API_TOKEN generation (Windows parity with setup.sh)

backend/.dockerignore

@@ -0,0 +1,11 @@
+.git
+.env
+.env.*
+!.env.example
+__pycache__
+*.pyc
+content/
+node_modules/
+dist/
+*.log
+.DS_Store

backend/app/config.py

@@ -10,7 +10,7 @@ class Settings(BaseSettings):
 
     # Auth
     secret_key: str = "change-me-in-production"
-    algorithm: str = "HS256"
+    crawl_enabled: bool = False  # Set CRAWL_ENABLED=true to start program crawl scheduler
     access_token_expire_minutes: int = 1440  # 24 hours
     api_token: str = ""  # MCP connector auth — generated by setup.sh
 

backend/app/main.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import asyncio
+import sys
 import logging
 from contextlib import asynccontextmanager
 from fastapi import FastAPI
@@ -27,6 +28,13 @@ async def lifespan(app: FastAPI):
                 logger.error("Could not initialize database after 10 attempts — starting without tables")
 
 
+    # SEC-05: Fail fast if SECRET_KEY not configured
+    from app.config import get_settings
+    _s = get_settings()
+    if _s.secret_key == "change-me-in-production":
+        logger.error("CRITICAL: SECRET_KEY not set. Run ./setup.sh or set SECRET_KEY in .env")
+        sys.exit(1)
+
     # Run lightweight migrations for schema changes
     try:
         await run_migrations()
@@ -41,14 +49,17 @@ async def lifespan(app: FastAPI):
     except Exception as e:
         logger.warning(f"Resource seeding failed (non-fatal): {e}")
 
-    # Start background crawl queue scheduler
+    # Start background crawl queue scheduler (gated on CRAWL_ENABLED)
     crawl_task = None
-    try:
-        from app.services.crawl_scheduler import crawl_queue_loop
-        crawl_task = asyncio.create_task(crawl_queue_loop())
-        logger.info("Crawl queue scheduler started")
-    except Exception as e:
-        logger.warning(f"Crawl scheduler failed to start (non-fatal): {e}")
+    if _s.crawl_enabled:
+        try:
+            from app.services.crawl_scheduler import crawl_queue_loop
+            crawl_task = asyncio.create_task(crawl_queue_loop())
+            logger.info("Crawl queue scheduler started")
+        except Exception as e:
+            logger.warning(f"Crawl scheduler failed to start (non-fatal): {e}")
+    else:
+        logger.info("Crawl scheduler disabled (set CRAWL_ENABLED=true to enable)")
 
     logger.info("Fitness Rewards backend started")
     yield
@@ -68,7 +79,7 @@ app = FastAPI(title="Fitness Rewards", version="1.0.0", lifespan=lifespan)
 app.add_middleware(
     CORSMiddleware,
     allow_origins=["*"],
-    allow_credentials=True,
+    allow_credentials=False  # Bearer tokens don't need credentials mode,
     allow_methods=["*"],
     allow_headers=["*"],
 )

backend/app/schemas/auth.py

@@ -1,17 +1,17 @@
 from __future__ import annotations
 
-from pydantic import BaseModel
+from pydantic import BaseModel, Field
 
 
 class LoginRequest(BaseModel):
-    username: str
-    password: str
+    username: str = Field(min_length=3, max_length=50)
+    password: str = Field(min_length=8, max_length=128)
 
 
 class RegisterRequest(BaseModel):
-    username: str
-    password: str
-    display_name: str
+    username: str = Field(min_length=3, max_length=50, pattern=r'^[a-zA-Z0-9_-]+$')
+    password: str = Field(min_length=8, max_length=128)
+    display_name: str = Field(min_length=1, max_length=100)
     email: str | None = None
 
 

backend/app/utils/auth.py

@@ -13,6 +13,7 @@ from app.config import get_settings
 from app.database import get_db
 
 settings = get_settings()
+ALGORITHM = "HS256"  # Hardcoded — not configurable for security
 oauth2_scheme = OAuth2PasswordBearer(tokenUrl="/api/auth/login", auto_error=False)
 
 
@@ -27,7 +28,7 @@ def verify_password(plain: str, hashed: str) -> bool:
 def create_access_token(user_id: str, expires_delta: timedelta | None = None) -> str:
     expire = datetime.now(timezone.utc) + (expires_delta or timedelta(minutes=settings.access_token_expire_minutes))
     payload = {"sub": user_id, "exp": expire}
-    return jwt.encode(payload, settings.secret_key, algorithm=settings.algorithm)
+    return jwt.encode(payload, settings.secret_key, algorithm=ALGORITHM)
 
 
 async def get_current_user(