Feat/issues 1043 1044 1045 1046

[aladi11isah]

Summary

Implements protocol fee rate management in Treasury contract and ensures market creation events are properly emitted for indexer compatibility.

Changes

Treasury Contract (Issue #1043, #1044, #1045)

• set_fee_bps: Admin-only method to update protocol fee rate with ceiling validation (max 10000 basis points)
• get_balance: Read-only method returning current treasury escrow balance
• withdraw_fees: Admin-only method to sweep accrued fees to recipient, logs withdrawals, returns amount withdrawn
• Cleaned up ~400 lines of duplicate code
• Added storage key for fee rate (FEE_BPS)

Market Contract (Issue #1046)

• Emit market_created event in Market::initialize with:
  • Topics: (Symbol("market_created"), market_id)
  • Data: Full Market struct for indexer compatibility
• Fixed Market struct initialization (removed duplicate outcome field)

Documentation

• Added contracts/README.md with:
  • Event reference table with topics and data payloads
  • Storage key mappings for all contracts
  • Error handling and type definitions

Testing

• 6 unit tests covering success paths and error conditions
• Authorization and validation tested
• Edge cases handled (ceiling exceeded, double initialization, unauthorized access)

Closes #1043
Closes #1044
Closes #1045
Closes #1046