chore: add PumpSwap AMM and pump fees IDL files

Reference IDLs for the PumpSwap AMM program (pAMMBay6oceH9fJKBRHGP5D4bD4sWpmSwMn52FMfXEA)
and pump fees program. Used to verify on-chain error codes and account layouts.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

Author: smypmsa