### Check for existing issues

- [x] I have searched the existing issues and checked that my issue is not a duplicate.

### What happened?

### Title Unbelievably brain-dead design. Your rigid parameter blocking is literally bricking compliant clients. Fix this garbage.

### Body

**Describe the bug** Let's cut the polite crap: who in their right mind thought it was a brilliant idea to have a gateway hardcode a parameter whitelist and throw a `400 UnsupportedParamsError` for standard parameters?

Right now, sending a completely standard parameter like `reasoning_effort` to a premier provider via `deepseek-v4-pro` results in LiteLLM completely bricking the request. The client is 100% compliant. The upstream provider handles it perfectly. Yet, LiteLLM sits in the middle like a clueless, nosy middleman, blocking production traffic just because it doesn't recognize the parameter.

This stupid restriction serves absolutely ZERO purpose. It is purely redundant, patronizing, and utterly brain-dead.

**Why this design is a joke:** A gateway is supposed to be a transparent pipe. It routes, it authes, it stays out of the way. It is NOT your job to play "parent" to the client or to "protect…