Additional minor fixes from audits

[pileks]

bid_wall

• close_bid_wall: SOL from closing quote token account now goes to authority instead of payer

futarchy

• conditional_swap: Added comments explaining intentional token:: usage (no code change)
• spot_swap: Same — added comments explaining intentional token:: usage (no code change)

v07_launchpad

• fund: funder_quote_account constraint tightened from token:: to associated_token:: (ATA only)
• fund: Expiry check changed from >= to > (rejects funding at exact expiry second)
• set_funding_record_approval: Approval period check changed from >= to > (excludes exact final second)

price_based_performance_package

• PerformancePackageState: Removed unused Unlocked variant (no accounts on mainnet use it)
• initialize_performance_package: Tranche total uses checked_add instead of .sum() (new error: TotalTokenAmountOverflow)
• change_performance_package_authority: Switched from emit! to emit_cpi! (adds event_authority + program accounts)
• execute_change: Switched from emit! to emit_cpi! (adds event_authority + program accounts)
• propose_change: Added common: CommonFields to ChangeProposed event; now increments seq_num
• README: Updated to reflect removal of Unlocked state