Goal: the position lifecycle — split collateral into YES/NO, merge back, redeem winnings after resolution.
S2.1 ✅ CTF cycle (split / merge / redeem) tested; redeem after a manual resolve works in the demo.
splitPosition (USDC → YES+NO), mergePositions (YES+NO → USDC), redeemPositions
(winning tokens → USDC after reportPayouts).