Add negative regression tests for MARKET / CONDITIONAL / TPSL order validation

[vikions]

Hi,

while looking through the current starknet branch, I noticed that the tests under tests/perpetual/order_object/ seem to cover the happy-path construction/serialization cases, but not the invalid-input validation branches in x10/perpetual/order_object.py.

A few examples of rules that are currently enforced in code:

• MARKET orders must use time_in_force=IOC
• MARKET orders must not be post-only
• CONDITIONAL orders must include trigger
• TPSL orders must be reduce-only
• TPSL orders must not be post-only
• POSITION TPSL orders must use synthetic_amount=0
• TPSL orders must use price=0
• tp_sl_type is required when take_profit or stop_loss is provided

It looks like a small tests-only PR could add pytest.raises(...) coverage for these existing checks without changing behavior.

If this direction makes sense, I can put together a narrow regression-test PR.