Add direct reserve deposits with split allocations

Summary

Added atomic single and split reserve deposits, exact allocation validation, ledger-derived balances, filtered deposit history, and an accessible Reserves page workflow without affecting normal financial analytics.

Decisions

• Represent each deposit as one reserve operation with one positive entry per distinct active reserve
• Keep direct reserve deposits outside normal transactions and derive operation totals and reserve balances from entries
• Lock all targeted reserves in deterministic UUID order before creating the operation and allocations

Learnings

• Using the existing exact JSON money path prevents rounding, over-precision, and numeric overflow from entering the reserve ledger