praisonai-platform: JWT signing key defaults to hardcoded "dev-secret-change-me", allowing token forgery for any user when PLATFORM_ENV is unset

PraisonAI Platform is the platform layer for the PraisonAI multi-agent teams system. Versions prior to 0.1.4 have an insecure default cryptographic key. The JWT signing secret defaults to the hardcoded literal `"dev-secret-change-me"` when `PLATFORM_JWT_SECRET` is unset. A safety check exists but only fires when `PLATFORM_ENV != "dev"`; the default value of `PLATFORM_ENV` is `"dev"`, so the check is silently bypassed in any deployment that does not explicitly opt out. The attacker reads the literal from this public source file, mints a JWT with arbitrary `sub` and `email` claims, and authenticates as any existing user (including workspace owners and admins). PraisonAI Platform version 0.1.4 patches the issue.