Fix local startup defaults and add MVP tests

.env.example

@@ -1,9 +1,9 @@
 # Core
 DB_PASSWORD=mastermind
-DATABASE_URL=postgres://postgres:${DB_PASSWORD}@db:5432/mastermind
+DATABASE_URL=postgres://mastermind:${DB_PASSWORD}@db:5432/mastermind
 
 # Public base URL (set to https://... when live)
-BASE_URL=http://100.101.78.42:3005
+BASE_URL=http://localhost:3005
 
 # REQUIRED in production (>=24 chars). Generate with: openssl rand -base64 48
 SESSION_SECRET=change-this-to-a-long-random-string
@@ -15,8 +15,8 @@ TRUST_PROXY=true
 COOKIE_SECURE=false
 
 # One-time bootstrap local owner (only used if there are no local identities yet)
-BOOTSTRAP_OWNER_EMAIL=
-BOOTSTRAP_OWNER_PASSWORD=
+BOOTSTRAP_OWNER_EMAIL=owner@local
+BOOTSTRAP_OWNER_PASSWORD=owner
 
 # Google OAuth (optional)
 GOOGLE_CLIENT_ID=